A really easy way to get your colors to play nicely together is to find a print that you just love. Then find fabrics that are predominantly each of the colors in the one you love. Hopefully this will include a light, a medium and a dark fabric. Now whether or not you use your fabric you love, you will have ones that should coordinate with it and with each other.
Oh, and if you can't find one that 'matches' your inspiration fabric, go a few shades lighter or darker and you may find that works better.