I normally secure a food source, make a bed, get a stack of wood (in no particular order), make a miner's and digger's backpack if I'm able, scout for a decent area to make a base, drop off all the plants, saplings, pumpkins and the like I find in a chest, then head underground. I don't come up until I run out of space, run out of food, or run out of wood. With Tinker's construct, you can make torches with stone, so not a lot of wood needed except for replacement tools. Along the way I make an iron pick and iron armor.
Starting energy sources tend to be what is available to me. If I have more than 1 oil well nearby, I go that route. If I find a bunch of lava underground, I'll do that. Other times it is just a tree farm or other renewables. As far as engines, boilers or such, I try and do something I haven't done before. In this world, I'm going MFR and golems for my main resource generation, and I've decided to go all steam power (as much as possible), and only use EU and MJ where I absolutely have to. I haven't built a large boiler yet, (I have the materials), but instead am still working on building the base.