I've been making and using a 5 to 6 inch wide strip of 1/2" plywood with a series of 5/8" holes drilled every inch and a 1/4" hole centered 1" above and below the last. To use it I clamp or screw the jig to the cabinet (had to screw it in a large cabinet when the request for adjustable shelves came after installation):BangHead:
To use, I chuck a 1/4" spiral bit in my plunge router with a 5/8" guide collar, set the depth of cut. You must remember to add 1/2" to allow for the plywood. Then I just go along putting the guide bushing in each hole and plunging the router. The spiral bit cuts very clean holes. With the 1/4" holes at the ends, I can use a 1/4" drill bit or 1/4" centering tool to advance the jig for a longer set of holes.:eusa_danc
I must say I discovered the first one I made did not have the holes drilled exactly 1 inch apart after having used it for a whole set of cabinets - this was not a problem because as long as all four sets matched, no one would notice that one set of holes was really 1 & 1/16" above or below the other.
I now use a small double square to lay out the line for drilling. The blade is 1" wide, I set the square to draw a line the length of the plywood, then use the width to draw cross lines at 1" intervals.
In use there is no destruction of the jig since only the guide busing touches the plywood.
A nice touch is to go over the holes with a reamer to very slightly flare the outside of each hole. The spiral bit cut cuts such clean holes, it can be difficult to get shelf pins started in the hole. ;-)