If you get the height just right (have it just clear your head), then putting up or taking down the bike is a snap. One key is to not do both wheels at once, because then you're doing a balancing act with the bike high above you.

That is, when taking it down, put your hand on the saddle, unhook the rear wheel, rotate the bike down so it's hanging from the front wheel. Then put your hand on the seat tube, and unhook the front, lower it down, and rotate it to wheels down.