I'm fairly new to CPAP (two weeks in). So far it's been easier than I expected. I'm using a P10, which has generally worked great (once I got the correctly size pillows, that is), with one problem - I end up breathing through my mouth sometime early in the morning, after not breathing through my mouth most of the night. I've attached a screenshot from sleepyhead that shows the problem fairly well.
My hunch is the answer is to try a chin strap (I've ordered one and it will be here on Monday), but is there anything else worth trying?