As an old Hammond grinder of yore, yer basic jazzy sounds a la Jimmy Smith, McGriff, McDuff, etc. consist of having the first three drawbars full out and a decent dose of third harmonic percussion applied. Another one is to have the drawbars starting out witht he first one at full (8) and progressively decreasing them down to (1) at the centre of the row and then increasing them progressively back out to (8) at the last drawbar - gives you that nice 'whistly' top end - great with the big fat chords. Like many other things in music, there are no hard and fast rules, just pull 'em around.

Most of the jazzers used very little vibrato, but were tasteful (for the most part) in the use of the leslie rotors. Also, be wary of too much reverb, you'll sound tighter and fatter with just a minimum applied. Listen to some of the guys I just mentioned, you'll soon get the idea.

Happy jazzin'
BR