hi - i've just picked up my old woven sling (see "protect your braid" posted previous) for a few casts and it's far more accurate than my bowline loop sling. in fact yesterday i hit about within a CD sized target at 6-10 metres more often than not. that was with sidearm release AND apache!

so top tip for accuracy is to practise with one type of sling for a few months then switch to another kind, or different length etc. either you will notice an improvement or it will be worse. by this method you can eventually arrive at the sling that suits your musculature and the way you move and think, (if that's the right way to put it) rather than persist with one which needn't necessarily give the best results.
then try varying the grip - use one system for weeks or months, then try a change. by moving the retention loop to my little finger and having the release cord across my palm i increased accuracy. some people might get an increase by another means, but don't try too may things in one day or any improvement will be hidden.

sv