You need to do two things. Have deep pockets and cut out what isn’t absolutely necessary. While in school I usually go purseless, it’s hard enough trying to balance a backpack, laptop and textbooks without adding a purse in there.
Of course when I am down to necessary stuff, I only have ID and a couple of cards in my wallet (library, grocery, bank… no credit cards yet), lip balm and keys. When I carry a purse it’s usually because I don’t have the pocket space (as with dress pants) or want to carry a book. While working I need a purse to carry whatever I might need on break so I don’t have to run to the back (book, granola bar, extra makeup).
I can’t imagine carrying my check book everywhere with me. I only use a few a month for bills, the rest is debit or cash.