Small economies
I have a business money market (interest-bearing savings-like) account that I deal with strictly by mail. I use it for "small receipts" as sort of a rainy-day fund, and for occasional small disbursals.
I get one "business reply mail" envelope with each monthly statement to send in deposits.
Interest bearing what it does now, it doesn't pay for me to send in the small checks as I receive them; instead I hold them until I get my monthly statement, and send a wad of them in at once. The amount of interest I lose in holding the small checks is less than the cost of a stamp (right now).