The simplest, easiest & quickest way is to use a small gold pan, sometimes referred to as a "finishing" pan. Put a drop or two of Jet Dry (or any liquid detergent/soap) in there to lose the surface tension, but only a drop!
Just keep at it, you'll get better and quicker the more you do it with theses small pans.
To recap:
1. Bring home your sucker bottle / container with gold and black sand.
2. Use a small pan to separate gold from sand (not all black sand is magnetic).
3. Use a drop of liquid soap or Jet Dry.
4. Keep at it, the more times you do it, the easier and quicker it'll get.
5. Suck up the gold minus black sand in to sucker bottle
6. Put gold into little glass bottle for keeping.
Just my 2 oz. worth!