Require all laws passed by congress to have a sunset clause. Currently laws are passed and unless modified by a newer law remain on the books.
Each law would then have be renewed giving the public and congress an opportunity to evaluate the laws effectiveness. It would also stop the build up of laws that are bad law or no longer applicable.
Laws currently in effect would be added to the review process. Congress would have to renew old laws. Any law not renewed by a defined date would cease to be law.
As an adjunct to this, I would require that the number of laws be capped at 50% of the current number. That is, no new laws can be created until the current number of laws has been reduced by 50%. After that, if you want to add a new law, you must retire an existing one first.