I put it into my budget every month & use PNC Virtual Wallet's "Wishlist" feature to keep the buckets of money. It might be overkill, but I like it. I have sinking funds for the car ($40, as ours is new & this is mostly oil changes & registration/parking sticker), dogs ($130/month, which goes about half to food and half to vet expenses as they come up), travel (varies, based on whatever trip we're planning, but is minimum $200/month to account for camping trips, visits home to mom & dad, etc.), and gifts ($125/month).