I started out jelqing for a good while (maybe 1/2 year) hoping for more length which turned out to be negligible but it did add some girth - which I wasn't looking for (as I was sticking to the 'length first girth afterwards' rule).
So because of that and because jelqing by hand has become quite difficult w my girth I switched to pumping. Going from 20 mins to almost a full hour over time - releasing now and then to re-adjust. As I soon filled out the pump girth-wise I decided to continue in what was basically too small a pump hoping it would force some length gains; it didn't work that way and after a while it simply got painful in there ;-)
These days I am doing a combo of jelqs with a jar lifting device (see my history) and pumping in a bigger cylinder in sets of 15 mins 3-4 times a day - with the occasional day off. Whether that will work and give me some more length only time will tell
As it is I have already exceeded my girth goals, going from 5.6-5.7" to somewhere between 7.2 and 7.8" (see signature). To your question of what contributed the most - well, it seems all I do only ever gives me girth and more girth. So from my point of view your gains are going to have SOOO much to do with your genetic make up or whatever.
Hope that answers your questions