I just googled for cork sheet, found a local dealer and had them ship me some. I placed the track on the sheet, marked where I wanted cut lines (about 1/4" from the edge of the ties) and then cut it using a utility knife. Finally I sanded the edges with rough sand paper to get a nice bevel. Rubber cork sheet is difficult to sand, but normal cork is quite easy. Sanding it myself also allows me to get a nicer bevel than the typical 45 degree bevel on commercial products which is a little too steep for my liking.
Anyway, using this method is easy for turnouts, especially multiple turnouts in a row or crossovers and so forth. One thing it lacks is drainage ditches, but this should be less obvious in n scale.
Just an idea. My 2c worth.