96,
For me three things help my skimming...
1. Pointing all the returns so that they try and make the pool water swirl like a giant toilet bowl, but obviously much, much slower. This helps drag the debris in front of the skimmer.
2. Operating weir doors.. Weir doors are between the mouth of the skimmer and the skimmer basket. The weir door is what makes the skimmer 'skim' the surface of the water where the debris are.. Without a weir door, your skimmer is only about 50% effective.
3. Water level. Skimmers work best when the water is very low, and work poorly when the water is very high. You don't want your water level to be too low for fear that it will go below the skimmer, so the best compromise is right in the middle of the skimmer's mouth.
Thanks,
Jim R.