Cleaning Out Backup Files

I have some backup files that are not necessarily generated on a daily basis - so I want to ensure I keep a certain number of backup files. I have tried to do this but cannot get it working. I recall there was an example in these forums but cannot track this down. Any suggestions? Appreciate any help.

First off, please do not post questions in the Tips forum. That is for people providing tips. The sticky article at the top of that forums says not to do this.

As for your question, you can do something like "Date added is not among the X most recent, Move to trash" which will move anything that isn't among the X most recent files.