Well, of course several bows and leads, just in case, your pin brush, chop stick pick or comb to part their back, paper towels, wet wipes, food/water, x-pen, tack box, towel, table, no purse, but money/coins in waist pouch or something to hold money in (just not large), scissors, bands/scrungies and clips to hold hair back from face, medical kit (had a friend one time whos dog was injured and the kit would have come in handy). I was going to start with just a few things, but the whole thing became a long list. Don't forget your chair and canopy if outside.
I quess the most important thing is the first-aide kit.
Best of luck and remember to have fun!!
T.