Do you do your harness up so tight you can hardly breath in an attempt to keep it where it should be - or do you have it looser - so that it can ride up and also side to side - but makes it heaps easier to slide down after it has ridden up?
Have a seat harness which does the trick - have a waist harness that is pretty good - but no matter how tight I do it up it does eventually ride up - so the question is do you accept this and leave things a little looser so its easier to adjust when ready???