The general guidelines we suggest for tapering are reductions of no more than 5-10% of your total daily dose every two weeks or so to keep withdrawl symptoms to a minimum and to allow you to stay functional. If you haven't already, I suggest you take a look at The Ashton Manual which the resource we rely on for tapering guidance. Here is the link:
The Ashton ManualComing up with a good taper plan before beginning is wise [...]. And I'm glad you are on Valium since Ashton leans heavily in the Valium direction for tapering.
