Placing a pond skimmer near some ornamental grass or lilies planted along the edge of your pond helps to hide the skimmer and maintain the natural look of your water garden. Additionally, plants that have foliage overhanging into the water act as a natural trap for debris. This limits the amount of time leaves spend circling around your pond before being caught by the skimmer.
If your pond is not of the hard shell variety, you may consider adding a small cove that wraps around behind a shrub or other focal piece that hides your skimmer. This has the added benefit of allowing you to spend less time covering the top of the skimmer with stones or other camouflage, and makes it easier to access for maintenance and repair. A small cove also acts as a natural trap for floating debris, because water is the stillest in this section of your pond.
A stack of pond stones or river rocks can serve as a hiding spot for your pond skimmer. Install the pond skimmer according to its instructions, and then stack stones as naturally as possible around the area to hide the skimmer from view. Alternatively, if the pond skimmer lies flush with the ground, you can glue foam stones to the surface of a small piece of plywood, which creates a natural-appearing cover for your skimmer.
Overall, you want to place your pond skimmer where it is going to be the most effective. If you are adding a pond skimmer to an existing pond, opt for function over form when placing your skimmer. If you have a large pond, you may find a collection of debris in the section furthest from your fountains or waterfalls. Locate your skimmer where it will perform its function most efficiently, and do your best to hide it from view.