one trick is to use patterns all from one line where they're all made to work together. you can't go wrong! i would probably throw in one more solid to finish it off.
[studio mcgee mix and match]
[laid back cool]
another idea - pick one color palette and stick to it but mix up patterns both in scale and type.
sometimes what works best feels counter intuitive. opposites attract and the unexpected mix makes this combo a winner. the mud cloth is funky but the colors are subtle. the pinstripe is classic but the olive color makes it interesting. and the pink pillow softens the whole thing and makes it pretty. you might see this one again in the future, just sayin!