What's the right way to cook in a Crock-pot?

I love to cook with a crock-pot but sometimes my meat comes out too soft or there is way too much liquid in the pot like if I decide to make BBQ chicken in the pot. I seen other peoples crock-pot meals and they come out perfect so how do you get perfect crock-pot meals? The only thing I cook in the pot that comes out great is a roast with veggies.