IDEA: Pay your employees to tell you publicly or privately where your firm wastes money.

It sounds simple but your employees know generally what and where you are wasting money.  They observe it every day and do not get involved because they do not want to invite problems with their job.   Privately ask them. They can submit their ideas anonymously or privately and you can give them bonuses for their participation. Make it easy for them to tell you. Award good constructive comments, publicize the gift campaign and then see how many ideas you get.