Billing for cleanup of property

[Jason C.]

Usually when a tenant leaves a mess in a rental, I take it on the chin and clean it up, keep the full security deposit, and move on. They never leave a forwarding address anyway (if the property is a mess). The question is, if I wanted to account for and bill for the cleanup of the property, how should I estimate what to charge them?

I do the work myself. In this most recent case, I spent about two hours loading all the junk from the yard onto my trailer (it filled a 16 foot flatbed trailer) and will take it to the dump this weekend. Obviously there is the cost at the landfill, but how should I estimate the charges for unskilled work I chose to do myself?