How do you decide how much of your tenant's deposit to return?

[Steve S.]

They took pretty good care of the house. Appeared to have the carpets cleaned and the home cleaned. Deposit was 1 months rent. 

Thoughts?  How do you determine how much to return?  Do you use it for finding things like changing the locks?

[Eugene Kemp]

Don't be petty. If they left it right, give it all back. If you don't, be prepared to defend any amount with an actual cost to fix.