I tip the tray to put developer mostly at one end. Then I slip the print in under the surface face up at the other end, and gently release the tray so that a wave of developer washes over the print ensuring that it is completely covered by liquid. Then I keep a gentle rocking motion going for constant agitation. If any part of the print rises up, I gently push it down with tongs, or fingers, or gloves, depending on what I'm using. It's the most even development I can obtain (I've tried face down).

It seems to me that flipping the print multiple times is unnecessary and greatly risks damaging the print. The emulsion develops top down with the liquid penetrating very quickly (in seconds). Development upwards by penetration through the paper is neglible to the point of being non-existent. In any case, RC papers have no penetration through the base, showing how unnecessary it is.