I have a problem with referendums in one respect. We have a system whereby the constituents vote for an MP and then they should respect our views. A referendum is basically a vote of no confidence in our MPs regardless of the outcome.
But, I think there should be some mechanism whereby big, important decisions are voted on within constituencies and then that MP has to represent the majority view of the constituency. For example at election time some issues to be debated and regardless of party policy, that MP has his or her policies decided by the constituents. I'm not sure how it would work but it would avoid some of the 'whip' deciding which way to vote issues and it would also avoid some parties being able to block votes.
I hasten to add, it would probably create anarchy