Determine the first note of the trill by looking at the music. In Baroque music you will start a note above the written pitch; other music uses the written pitch.
Consult the trill-fingering chart to see whether the notes you must trill appear. If they are not listed, it means that the normal fingerings should be used.
Practice the trill slowly by alternating between the first and second note. Once you have a clean transition to each note, gradually increase the speed until you are playing the trill rapidly.
Decide how fast to play the trill based on the type of music. If the music is slow, play a relaxed, slower trill. If the trill is fast, increase the speed.