murathan
Was a Bassoonist
I dont recommend to use mirror because it makes an addiction hard to get rid of. You must eventually learn to jump by feel. There is always a risk of landing wrong. However you will learn in a song to make long jumps somewhere in your progress. Another idea is to do long jumps by passing fingers over the bass buttons touching them (without pushing them). Thisway you be sure where you are. You can also skip the last "pah" in an "oompah" move to gain jump time nobody will notice. We used that in a couple of student pieces with long jumps. It works (For example F-E jump) 
