Me and pull-ups are in a fight.

I went from being able to do no pullups at all to now being able to do 5, or one plus 14kg. I stand on a aerobic step so my arms are only just bent, I'm too short to reach the bars from standing on the floor
I found the assisted pullup machine / bands / inverted rows no help at all, after doing them for months I still wasnt any closer to doing a proper one. What did it for me was jumping up, holding up at the top for as long as possible, then lowering really slowly. I started with chin up narrow grip, then when I could do a few of those tried the normal wide grip. I do a few every time I go to the gym now, trying to get up to 10 wide grip. I find that if I do a few weighted ones first, then the normal ones seem much easier :-)