Instead of going by marks on your fence, have a long enough fence so you can clamp stop blocks to it. When you drop the work on a spinning bit, there is always the possibility that the work will get grabbed and pulled out of your hands. A stop block will prevent this. They also give you a positive place to start and end the cuts that will be consistent. Being against a block in starting and finishing the cut gives more control in dropping on and lifting up. You aren't sneaking up like you have to with marks. You can keep a more fluid motion going which will help with burning. Anytime you stop, you will burn, so the idea is to keep motion going. With blocks you can start moving as soon as you drop on and lift off without stopping. I've seen too many hands cut up because of trying to align with marks or I wouldn't have said anything. A hand held plunge router with a template guide and a template attached to the cutting board is another good method since the motion can be continuous. You can do shaped grooves with templates, too.