I don't necessarily recommend this method.

Don't use cash -- make sure everything is paid by one credit card and electronic bill pay. Then log in to my credit card and bank, and use that as my ledger. It says how much money was spent and the vendor, and from that I can usually tell what it was for.

Essentially, it's a poor man's Quicken. The trick for me is to not use cash, because that can't be tracked electronically.