spinnach lots of it !!!!!!
7 to 1 does it for me with 16m2 now and 18.5m2 in past , if your a chicken wimp and can't get last bit in , bend legs wrap sheet around hand with arm at full extension ,then straighten legs /back and that should get you the all important last few inches , if that don't do it you hadn't got enough in in the first stage , if you can't manage that its off to the gym for you !

when you eventually find your full in ideal sheet position , mark it so you can repeat it , you would also be suprised in the difference you pull with each arm.

good luck , it makes all the difference ,

when you get strong they used to say you can't oversheet a cat main , i can a mark is important here too !