How to formulate prayers to Saints?

How should my prayers be formulated? Is it acceptable if I ask a saint to help me in a certain moment? I understand that they pray for us, but when I'm praying to them, is it acceptable to pray something like "St Peter, help me with my problems" instead of "St Peter, with your prayers help me with my problems"? During my prayers, can I avoid words like "intercede" and "pray"?