I learnt a forearm grip first, but my ability to do it is highly seasonal. I tend to have sweaty hands and I slip more in this grip. So I can do it in winter but not in summer. I think it's because I can't get my hips as far from the pole, so there is more force running parallel to the pole, and I'm more reliant on hand friction. It seems that for my sweaty hands, the further I can get my body from the pole, the less slip I have. Plus, if I do slip, I'll flip over onto my feet instead of sliding down the pole head first.
My elbow grip is slightly better than a forearm grip in the summer, but there's still the same problem of not being able to get my body as far from the pole.
The easiest grip for me is the twisted split grip, as you can see in my profile pic. I can hold it for over 10 seconds (I usually get bored and start trying different stuff from there which is how I lose my balance). Veena, I promise I'm very careful with it, never kick up, don't practice excessively, stretch forearms, etc. :)
I just got a split grip jacknife and can push into a straightedge for a few seconds (yay!) No aysha for me yet thanks to my injured hip. Once I've practiced the split grip a bit more I think I'll like it much better than the other grips. Yeah, it's been a long hard road to get any balance in it, but I suspect once I get it it will be more secure and less subject to the vagaries of the weather. Plus handsprings and cartwheels!