Forging ahead (the modded Minecraft thread)

After playing Minecraft for the past few days now, I finished my spree and now I'm back to creating artwork again. I know it's a bit of a cheesy game that gets boring quickly after a while, but ever since I figured out how to properly install mods in March, the game became a lot more fun again.

Use this thread to discuss any mods you like to use, any experiences you had with them, and any tips on how to use them to their full potential.

For me, I get a kick out of Biomes o' Plenty, Tinker's Construct, and the Twilight Forest.