Sophie mostly goes outside, but the pee pad is "back up" that she uses sometimes. (It came in veeerrrry handy this week when I was miserably sick with the flu and couldn't get her out as much as she needed.) I put the pee pad on a plastic "tray" that is actually a shoe/boot tray. I bought one to put just inside the front door for my wet shoes and rain boots, but the trays were sold two to a pack. At the time I didn't know what on earth I'd do with another shoe/boot tray, but I stuck it in the closet and figured I'd find a use for it. Well, turns out it's perfect for the pee pad! I do have to fold the pad sides under a little bit because the tray is narrower than the pee pad, but having to step into the tray seems to have helped Sophie realize when she's going on the pad/tray and when she's just on the carpet. Her "aim" has improved CONSIDERABLY!!
