Eclectic is cool; in fact, it is one of design's trendiest buzzwords. But if you pair a Southwest-style tin mirror with an English walnut dining table and add a prairie-style light fixture, you've probably gone over the line.
Solution: A restrained hand. You can't buy everything you love, any more than you can wear every piece of jewelry you own on the same day. Decide on your basic style, and then incorporate a mere handful of unexpected touches, rather than a circus of them.