How do I make multiple forge versions at once?

[21harrisont]

Let's say I have some 1.7 and some 1.8 mods. Obviously these won't work together. I launch minecraft forge in 1.8, but I get an error because some mods only work in 1.7 How do I only activate the 1.8 mods when running 1.8 without having to take out the mods and put them back in every time I want to switch versions. It's really a pain. Is there a faster way to sort the mods?

[Choonster]

Give each launcher profile a separate game directory.