Interior designers have seen it all. Check out some of their biggest pet peeves and see how to avoid them in your own home's design.

Appliances in a mishmash of finishes and time periods, like this kitchen on HGTV's Run My Makeover, irk designers.

Kitchens are about togetherness, and design choices should reflect that. Stainless steel appliances and chairs give a modern touch to this bright, contemporary kitchen. "Regarding the appliance finishes, I'd say the most important aspect is cohesion in finish," says architect and designer Jeff Troyer. "I don't necessarily need to use the same brand of appliance, but a matching finish is important." He offers one more tip: Make sure that when using different brands of appliances that the handles match.

Kitchens are lively spaces, so a designer pet peeve is when lighting is an afterthought. This before kitchen is seen on HGTV's Home Town.