High Level: Circle the area from different directions to determine the best possible landing site in the vicinity. Check the wind direction and speed using pools of water, drift of the plane, branches, grass, dust, etc. Observe the landing approach and departure zone for obstructions such as trees or high terrain.
Intermediate Level: Make a pass in both directions along either side of the runway to check for obstructions and runway length. Check for rock size. Note the location of the touchdown area and roll-out area. Associate landmarks with your landing area, to have a good sight picture to be used on final approach. Early morning or late afternoon sun casts shadows that yield the best conditions for determining rock size and, landing conditions. Similar to ski flying with an overcast sky condition, landing areas are very difficult to evaluate without shadows.
Low Level: Make a pass to check for cuts in gravel, rocks, dips, bumps, etc., that can’t be seen from directly above. It is important to be at an angle to the runway, not above it. Certain light conditions can make a bad site seem good. Check and double check any area not used before, or locations that have had high water since the last landing. Make another pass and roll one tire for a few feet to get a feel for the landing surface.