how to be a hero to your guitar player if you're a cheapskate: After gigs, pick up any guitar picks you see lying on the ground that your guitarist (or some other band's guitarist) dropped. Keep them on hand and hand them to your guitarist when he realizes he dropped his pick on the floor at the last show.
Also be mindful of other small, shiny objects on the floor that you can hand to your bandmates that might be useful: spare change, tuning keys, baggies of heroin, patch cables, etcetera. Remember the LEAVE NO TRACE philosophy! Handy money-making tip for when the venue screws you out of a guarantee: Pick up your drummer's broken sticks after a show, glue them back together and sell them back to him.