For organists, Bach's music is the beginning and the end.
Just about every organists' career starts and ends with it.
It is such a beautiful music that in order do it justice, you should really play it well.
In order to learn to play Bach organ works on a good level, you should do the following.
1.
Develop correct organ practice habits by creating a good long-term plan and sticking with it, practicing very slowly in fragments and in voice combinations.
2.
Develop your organ sight-reading skills by playing one unfamiliar piece of Bach's organ music per day in a slow tempo.
3.
Develop your organ technique by practicing scales and other exercises on the manuals and on the pedals.
4.
Learn to apply the articulate legato touch in Bach's pieces by leaving small rests between the notes.
5.
Learn to register the works that you study according to the rules of historical performance practice.
6.
Use toes-only pedaling and avoid finger substitutions and glissandos.
7.
Add historically correct ornamentation (especially in cadences).
8.
Choose correct tempo for performance so that your pulse and sense of meter would be obvious to your listeners.
9.
Memorize the pieces you are playing so that you know them by heart - this way you will defeat performance anxiety and reduce the level of fear to play them in public.
10.
Develop your music theory and harmony skills so that you would understand how the piece is put together.
Start applying these tips today in your organ practice.
With time they will allow you to master Bach's organ music on a level that you deserve.