I just spent a year trying to get surface debris to go in my skimmer. I'm about 90% there and can clear the surface in about an hour. FWIW here is what I've learned:
1) To get max surface flow into the skimmer, keep the pool water level as low as possible but not so low that air is entrained into the skimmer valve. I have a suction side pool cleaner and need to maintain a water height of 2 3/4" above the skimmer lip in order to prevent the hose being sucked into the skimmer and setting off the skimmer float valve. If you don't have a hose issue a water height of 1 1/2" should work well.
2) The direction the return jets are aimed is all important to good skimmer action! You want little or no flow from the return jets accross the face of the skimmer so that water flow into the skimmer wins. If you have too much water flow from a return past the skimmer then that flow wins and the surface debris is just swept past the skimmer. In other words you are aiming for a surface flow dead spot in front of the skimmer so that the water being sucked into the skimmer pulls surface debris from a large area around the skimmer.
3) My pool cleaner manual said to aim the return jets downwards, this definitely doesn't work for skimmimg!!! It creates surface dead spots and if, like me you have a return jet opposite your skimmer, the water from the jet hits the bottom of the pool, wells up on the opposite wall right in front of the skimmer, and pushes all surface debris away from the skimmer!
4) Your return jets should all point in the same direction, aimed parallel to the pool walls. so that you achieve clockwise or anticlockwise circulation around the pool. I found it best to have the return jet closest to the skimmer aimed away from the skimmer. I have a jet about 15' from my skimmer and when aimed downwards or towards the skimmer I got very poor action nomatter how much I fooled around with this jet.
5) The rate of circulation can be controlled by the angle of the jets. They should never be higher than horizontal, and as you move them below horizontal the rate of surface circulation will decrease. The last jet in the circulation loop that pushes debris towards the skimmer is very important. The goal is to get enough surface flow such that the debris floats into the dead zone in front of the skimmer and is sucked in, but not so much flow that the debris is swept past the skimmer.
6) I found that a quite slow circulation rate worked best, it allowed debris in the middle of the pool to move into the outer circulation loop, and not be pushed back into the middle.
7) Minute changes in the angle of the jets can make a big difference to surface flow, and it can take the pool a good ten minutes to fully adjust to a change. So only adjust one jet at a time and make very, very small adjustments. Also if you have a pool cleaner hose moving around the surface it too will effect surface flow directions
You just have to be patient!!
Hope this helps.
