The operator I worked for 99% of the time had some one else on to start me, or me to start some one else in the same manner as chumbo does.
However being a relatively small operator occasionally you had to start your-self and the boss had developed a procedure (over a decade or so flying Tigers) which worked quite well.
Chocks in front of both main wheels and rope that is attached to both chocks running back under the fuselarge and out behind left wing.
Tell passenger (who is already straped in) 3 times to keep hands away and not to touch throttle.
Prime and start as normal.
Turn other Magneto on and adjust throttle (via front seat throttle) if too high.
Hold firmly on to the centre struts and put one foot on wheel, next foot on wing-walk and climb over wing (safer than it sounds as with firm grip was very sturdy and easy to do).
Stand on ground right up against fuselarge and wing, with right hand on rear throttle grab pre-laid rope with left hand and give firm tug (some pilots are better practiced at this than others) and this will remove the chocks.
Stand on wing-walk and then climb in as normal (at this point we had our hand off the throttle for no more than 2-3 seconds).
Still not perfect but we did practice doing this a few times before we had to for real and in my opion as safe as any thing when done properly.
no one.