Aim to land somewhere near the numbers. Grass strips tend to be 800m or less, so avoid touching down two thirds up the runway. I know it sounds obvious, but it's amazing how many pilots used to mile-long runways don't realise they've less room to play with. But don't aim for the numbers at the expense of the nosewheel. I've witnessed more than my fair share of 'carrier' landings that ended in embarrassed pilot and shock-loaded engine. Keep that nosewheel up!
If you do end up floating two thirds down the runway before touching, don't be embarrassed about going round and trying again. Better that than an expensive trip into a ploughed field or through a thick hedge.
Cheers, jez