I never do any of the well-known, most efficient, seen everywhere methods of doing things. Even if it's the most efficient, too many of them rely on some mods or cross-mod interactions breaking the balance. "Balance" here being what I want to be my game's effort-to-gain ratio. Among other things I never use are: BC quarries, any turtle programs I don't write myself (builtins and code from the web), any kind of long-range teleportation (ender chests, tesseracts, mystcraft portals), mass fabricator (or matter fabricator), solar panels of any kind, Steve's cart tree farms, any metal- or oil-producing bees, nether lava pumping, centrifuging lava into metals, barrel sorting systems, soul shards (disabled on my server anyway), box-shaped rooms with a bunch of random machinery within, the entirety of Applied Energistics, and more...
I also never look up tutorials or guides on anything (except for reading the mods' wikis), I invent designs on my own and deliberately try to be different from the few things I already saw in someone else's videos. For me most of the fun is in coming up with a sophisticated machine and perfecting it down to be the fastest, most efficient, most compact possible. Not in building block by block something that somebody else did.
I keep a spreadsheet of all kinds of numbers for quick reference - fuel values in different generators, GregTech electrolyzer/centrifuge recipes, boiler size to fuel efficiency to heatup time to amount of fuel required to heat up, mob health and height to drop them to get them to 1-hit, and much more.