I marinate mine with soy vey sauce, then cook them covered with tinfoil for 25 minutes, then take off the tinfoil and cut through the thickest part of the breast to check doneness.

The tinfoil prevents drying out.

Uncovered. Baste them with a little butter or olive oil.

If I'm cooking boneless skinless breasts in the oven, do I cook covered or uncovered? Will they dry out? (Sorry - I'm a great cook, but I'm a vegetarian!)