In reply to geebus:
I'm still pretty new at this whole climbing thing, but someone showed me a good technique that really helped me on sit starts.
Sounds similar to things others have said, but here it is (and forgive me if I'm not using the correct terms etc):
Keep your arms straight, just hanging from the first holds.
Get your toes on the first two foot holds.
Rotate one knee inwards towards the other leg - this starts pulling you into towards the wall, and also raises you up a bit. You'll start bending this leg as you come inwards.
Once your hip is quite close in, you can push up on the leg which is now bent, or if not feasible you can often then pull forward to rock over onto the bent leg, and then push up.
Hope that makes sense.
But like others have said, if you don't like the sit-starts, don't do them
I don't always, but I try to if possible as its all good practise