Storage. I have an ender pouch as quickly as possible, and I've grown to enjoy the TE satchels. The ender pouch is instantly deathproof storage until better options arrive, then resorts to a delivery bag for my ME/Logistics Pipes system. The satchel are cheap, but small until upgraded. Enchanted with Soulbound and Storage IV (or whatever its called), the Resonant Satchel is a portable Diamond Chest that stays in inventory through death.
Tools, I usually opt TiCo, although that's mostly because I'm a creature of habit and I have them from early game already. If it weren't for my Lumber Axe, I would never have enough wood to do anything (before automation). I almost always carry a bow until I get decently into TC for a Silverwood Staff with at least a Lightning Focus. I prefer the Yeta Wrench, due to its scroll wheel abilities. Depending on the pack, I have an army of mining turtles controlled by a.wireless pocket computer. I love a hang glider until I have creative flight, and I keep one with my emergency gear always.
Armor, I'm wearing EIO Dark Steel (enchanted up the wazoo) set still, although I'm entering into both Blood Magic and Thaumcraft currently, so my Sanguine Armor is seeing some wear. I've not delved I to either mod too deeply, but I intend to see what both offer for options and compare. A friend wears Wyvern Armor and loves it, so I may play with that at some point as well, but it will wait.
I'm sure I'm forgetting something, which reminds me that I MUST have a Bibliocraft Clipboard on me at all times. Without an agenda, I wander aimlessly about, tinkering with this and that for hours without accomplishing anything productive. Sometimes this isn't bad, I suppose.