I check after every ride, part off a ritual that usually includes lubing the chain, replacing any consumables (tubes/Co2, etc), and gving things a once over before putting the bike away. I use a utility knife to probe cuts for bits of glass and pick them out if needed.

Deflating tires would make it harder to see the cuts, so that makes no sense to me whatsoever.

I'll also top the air in tires the night before an early ride- less to deal with in the morning. Since I start alot of my ride early, I know the bike is in good shape and ready to go.

Guys that show up to rides unprepared are a PITA. "It's time to go!" "Uh, does anyone have a pump?"