@PlowManPlow: When I wrote that, I didn't take in account that most modpacks were still made for 1.6, or that I forgot to say you should test them nonetheless.
Nevertheless, I would suggest you take the mods you wish to include in your modpack, put them into your regular Minecraft game and test it out. From there on, edit the configs in there, test it out again, and used the new config folder for your finished modpack.