I like to check my tires every couple of weeks. If the ride feels softer or a tire looks like it just came from a tire shop (underinflated) I check em too. I get lots of weird looks at work every time I say a tire is underinflated....I hate having to set them at the sticker pressure all the time. I like doing the semi tires where I can set them to 100-120 PSI
I keep my tires at 50 PSI MINIMUM