Not an option open to many people; but the best option for flying in, fixed-wing is the grass runway arrival. Last year I made the trip on Sunday with an extra pair of eyes on board (thank you George) but saw few other machines until we were close to Kemble. The only hazard was some complete moron flying the wrong way round the race-track holding pattern.
It's amazing how all the other traffic evaporates as you climb away on departure: even so, I am not convinced of the wisdom in following closely the published arrival/departure routes away from the immediate area around Kemble...