How about session limits?
Congress shall only be in session for three months a year. Everything that needs to be run through committee, debated, amended, voted upon, etc. has to happen in twelve weeks. And they all get bonus pay for every week early they adjourn.
Or
Each new term starts with a set number of "action points". Introducing a new bill costs some number of action points, as does attaching an amendment, proposing a measure, casting a vote, etc. At the end of the term, they have to publish a two page report summarizing how each action point was used and mail it to every household in their district.
