Lay Out Landscape Fabric, Add Gravel, Compact, Sand, Compact
Make sure there is some slope to your patio area to avoid puddling rainwater. The slope can be from side to side or from one end to the other, depending on your specific situation.
First, lay landscape fabric across the space to keep weeds at bay.
Spread crushed gravel on top of the fabric across the entire area, about 2 inches thick.
Compact with the power compactor. Wet with a house, compact again.
You'll need at least 2 inches of sand after it's been compacted. Spread sand across the entire area and distribute it evenly (Image 1) to the top of the forms. Drag 2x4s across the sand to ensure a level surface.
Use the power compacter to compress the sand firmly in place. Spray sand with a fine mist of water and repeat process until sand is packed tightly.