We always leave $2 a day for the 2 of us. Like someone else mentioned I put all the dirty towels in the tub, trash in the garbage and I make sure the vanity area is neat so they can clean around it.
We tip $5.00 a day. I also straighten up our personal mess so they can clean. We were treated with a Mickey wreath decorated with one of our santa hats,it was really cute! She also made a towel basket for our brushes and combs. It was fun to come back to our room to see our suprises.