never been a fan having learnt blind, but was forced to make a cheap and cheerful one the other day. used a cd case, very brittle plastic, tread carefully with the drilling.
http://s5.beta.photobucket.com/user/ringling87/media/DSC02503_zps94c3ac8b.jpg.html
it did the job, i thought it was the lever arrangement causing problems on a 3g114e, but it turned out that the tip of my cb e series pick was a bit bent. don't think i'd of ever got it true without a clear cover for a 114 and 114e, what a great bit of kit for tool making. time to make an era profit cover then an overlifter i think.