cutting in angles backsplash

Ok this may sound stupid but here goes. I am fairly new to the Stone (http://g603.net) industry. I do not fabricate, just install. WEll the other day I had a job where the top came up 4' over at a 45 about 4' then down the wall 8'. Easy enough to get the top in but then when it came to backsplash I had to miter them to fit the wall. This was difficult to do by hand (http://maplered.com) and (http://maplered.com) very time consuming. We made it look good but it could have been better. How do you guys cut your angles for backsplash?
_________________
Travis
CounterWise, Inc.