When dusting a horizontal surface, the dust can become too heavy on the surface. I use a can of compressed air to gently blow away any excess dust. Due to this, my lifts are usually clear of excess dust, which makes the print stand out better.
However, when clearing excess dust, I make sure I am several inches (usually at least 12)away before spraying the air. Doing this instead of blowing on the dust prevents any of your DNA from getting on the surface, in case you have to come back to collect DNA samples.