I'm not an expert on Minecraft or FTB, but I'm usually pretty good at answering my friends' questions in regard to most things associated w/ this game. I attribute it to having too much time on my hands at work and at home, but I also really like knowing what's going on in any game I play and being able to share that knowledge whenever possible. With that being said, I put this together as a reply to another post but ended up writing far more than I intended to. I don't think my format is excellent, and I could probably fix some wording / grammar but I tried! So here it is, my first and only impromptu guide to random exploration and stuff! 
GROWLE'S IMPROMPTU GUIDE TO RANDOM EXPLORATION & "STUFF"
note: I am currently using the Ultimate modpack, and besides that have only played Mindcrack and Vanilla. I also use Sphax BDCraft texturepack so if I mention anything that sounds off in terms of appearance, that may be a reason.
Unrelated to crafting, exploration / adventuring can still give you a very large early game advantage, so make sure when traveling that you investigate any potential loot areas! Often overlooked by many, opening your large area map and zooming all the way out once in awhile (default key X in packs I use, Z is for zoom) will help you spot potentially hidden / obstructed structures. The few things to keep an eye out for are not always obvious, but over time you will start spotting them easily.
Before gettting started on the meat of this "guide" I'd like to point out that I make it a priority to get a soul forge up ASAP due to the presence of soul cages in some of these areas, as well as the enormous advantages that soul shards can afford in the early / mid game. Considering you need some obsidian, soul sand, glowstone and at least 1 diamond, this may not be immediately feasible, but all you really have to do is get some iron armor, weapon of your choice, and find a ravine that has a few diamonds, or do a little digging...I make a diamond pick and equip it on a very easy to make mining turtle. "But Growle, 3 diamonds and some redstone are endgame!" I've heard people talk about the difficulty in obtaining diamond. Truth is, ravines are everywhere and any cave that takes you down to diamond level will invariably have diamonds, redstone, and whatever else is useful for you at the time. Depending on your game's difficulty setting, getting most mats is very easy with a healthy set of brass balls (yes, that is in bold). When starting a new map I will often find myself deep inside one of these caves with nothing but stone tools, a crafting table, 4 torches, and fully clenched cheeks. Loosen up though, we're here to have fun!
The following is what I normally do to maximize my exploration / adventuring experience and is in no way indicative of what SHOULD be done, as everyone plays differently. That being said, if you're not using exploits or cheaty methods, I recommend you maximize your early game potential by (at the very least) taking various approaches into consideration.
After some short forays into the wilderness around the spawnpoint I usually make a temporary home, but only if alone. If I somehow managed to convince one of my minecraft buddies to play, then I usually end up following them, if only to appeal to their overwhelming wanderlust...Basically (and this applies to two of them), if they don't find a place they LOVE from day one, they will forever regret their decision until they finally shut up and move...much to my chagrin.
After finding a place I do all the regular stuff, set up a bed, furnace, chests etc...As much as materials allow. Once I have some basic armor and tools, I head right back out, with my next (not so lofty) goal of getting a mining turtle or 2, obtaining nether / twilight access, and setting up the aforementioned soul forge. First I will go into the mining turtle, since they are easy to make and run, but many people still avoid them due to the stigma associated with LUA programming or whatever...Well, GOOD NEWS EVERYONE! You don't have to be a member of MENSA to run these puppies (but it does help).
Mining turtle basics (if you plan on making one): I will annotate any command which can have a variable number in parentheses...
These are an important starting tool in MY PERSONAL arsenal, and these amazingly affordable minions only require only 2 (very easy) commands. They are:
Excavate (#), or tunnel (#) with the number being any number you like, and a space between the word and the number. I will present an example...In any random area, place a wooden chest, and make sure the turtle's backside is against any side of that chest when you set him down. Provide your turtle some fuel, at this point it's easy to just use a little bit of coal / charcoal. Type your command (excavate or tunnel). The excavate function will dig a hole the width of the number you specify, so by typing "excavate 3," your turtle will dig down in a 3x3 hole, or if you input "excavate 7," he will dig a 7x7 hole. The chest is there for the turtle to dump its goods when its internal inventory fills up. The reason you have a diamond pick on this guy is because it allows him to instantly mine obsidian, without it dropping into lava by accident. In the time it would take you to mine 1 block of obsidian w/ a diamond pick, you could have set down a turtle and sent him on his way to collect that stuff for you while you sit back and cackle maniacally while sipping on your craft ale (cackling / consumption of alcoholic beverages is optional).
GROWLE'S IMPROMPTU GUIDE TO RANDOM EXPLORATION & "STUFF"
note: I am currently using the Ultimate modpack, and besides that have only played Mindcrack and Vanilla. I also use Sphax BDCraft texturepack so if I mention anything that sounds off in terms of appearance, that may be a reason.
Unrelated to crafting, exploration / adventuring can still give you a very large early game advantage, so make sure when traveling that you investigate any potential loot areas! Often overlooked by many, opening your large area map and zooming all the way out once in awhile (default key X in packs I use, Z is for zoom) will help you spot potentially hidden / obstructed structures. The few things to keep an eye out for are not always obvious, but over time you will start spotting them easily.
Before gettting started on the meat of this "guide" I'd like to point out that I make it a priority to get a soul forge up ASAP due to the presence of soul cages in some of these areas, as well as the enormous advantages that soul shards can afford in the early / mid game. Considering you need some obsidian, soul sand, glowstone and at least 1 diamond, this may not be immediately feasible, but all you really have to do is get some iron armor, weapon of your choice, and find a ravine that has a few diamonds, or do a little digging...I make a diamond pick and equip it on a very easy to make mining turtle. "But Growle, 3 diamonds and some redstone are endgame!" I've heard people talk about the difficulty in obtaining diamond. Truth is, ravines are everywhere and any cave that takes you down to diamond level will invariably have diamonds, redstone, and whatever else is useful for you at the time. Depending on your game's difficulty setting, getting most mats is very easy with a healthy set of brass balls (yes, that is in bold). When starting a new map I will often find myself deep inside one of these caves with nothing but stone tools, a crafting table, 4 torches, and fully clenched cheeks. Loosen up though, we're here to have fun!
The following is what I normally do to maximize my exploration / adventuring experience and is in no way indicative of what SHOULD be done, as everyone plays differently. That being said, if you're not using exploits or cheaty methods, I recommend you maximize your early game potential by (at the very least) taking various approaches into consideration.
After some short forays into the wilderness around the spawnpoint I usually make a temporary home, but only if alone. If I somehow managed to convince one of my minecraft buddies to play, then I usually end up following them, if only to appeal to their overwhelming wanderlust...Basically (and this applies to two of them), if they don't find a place they LOVE from day one, they will forever regret their decision until they finally shut up and move...much to my chagrin.
After finding a place I do all the regular stuff, set up a bed, furnace, chests etc...As much as materials allow. Once I have some basic armor and tools, I head right back out, with my next (not so lofty) goal of getting a mining turtle or 2, obtaining nether / twilight access, and setting up the aforementioned soul forge. First I will go into the mining turtle, since they are easy to make and run, but many people still avoid them due to the stigma associated with LUA programming or whatever...Well, GOOD NEWS EVERYONE! You don't have to be a member of MENSA to run these puppies (but it does help).
Mining turtle basics (if you plan on making one): I will annotate any command which can have a variable number in parentheses...
These are an important starting tool in MY PERSONAL arsenal, and these amazingly affordable minions only require only 2 (very easy) commands. They are:
Excavate (#), or tunnel (#) with the number being any number you like, and a space between the word and the number. I will present an example...In any random area, place a wooden chest, and make sure the turtle's backside is against any side of that chest when you set him down. Provide your turtle some fuel, at this point it's easy to just use a little bit of coal / charcoal. Type your command (excavate or tunnel). The excavate function will dig a hole the width of the number you specify, so by typing "excavate 3," your turtle will dig down in a 3x3 hole, or if you input "excavate 7," he will dig a 7x7 hole. The chest is there for the turtle to dump its goods when its internal inventory fills up. The reason you have a diamond pick on this guy is because it allows him to instantly mine obsidian, without it dropping into lava by accident. In the time it would take you to mine 1 block of obsidian w/ a diamond pick, you could have set down a turtle and sent him on his way to collect that stuff for you while you sit back and cackle maniacally while sipping on your craft ale (cackling / consumption of alcoholic beverages is optional).