Frankly no right or wrong answer to this question, and it ultimately comes down to personal preference. Some people like to flip their bacon when using a press, while others find flipping unnecessary.  If you do choose to flip your bacon, be sure to do so carefully so that you don't splatter hot grease everywhere. Bacon presses can be an excellent tool for achieving perfectly cooked bacon. They can also help keep your bacon from curling up as it cooks.  Whether or not you choose to flip your bacon when using a press is entirely up to you. Experiment and see what you prefer!