The APC has a checklist on their website. Make sure you print it out, and check off every little thing on that list, for every kit. Keep that list posted somewhere too - I always had it taped to the lid of the kit. Kits need to be somewhere easily accessible and not buried under loads of tack.
Everything must be labeled.
The HMH has a whole checklist that delineates every single thing that is to be expected at a rally: from stable management to turnovers to turnbacks.
As far as your horse - things that I remember being checked for: a clean sheath, clean mane, clean tail, clean hooves including sulcus grooves and nail holes. No dandruff or dirt between hairs, belly and elbows clean, no ear wax. Tack needs to be immaculate - no loose stitching anywhere, no cracks on the stirrup leathers, no missing keepers. If you have elastic girths make sure the elastic is clean and not worn down.
Did I mention everything must be labeled?
Every horse needs their own grooming kit - no sharing. Grooming tools must be clean and free of accumulated dirt. Everything must be labeled. Sponges (body and face), curries, hard and soft brush, hoof pick, etc.
Have a bridle and tack wipe down station, you will be checked for clean tack during turnovers. Always dip and clean the bit, wipe down and figure-eight the tack. We went overboard and always had each hook labeled with the horse’s name.
Stalls should always have the horse’s stall/name card and info on the door or front face of stall. Feed chart needs to be where the feed is stored – visible and legible. There should never be any manure in the stalls, and don’t leave pitchforks or buckets out in the aisle. Everything put away always. Pull rubber feed pans out of the stall when the horse finishes grain. We all would chip in and remove manure when we saw it. Any time you are in the stall the pony needs to be haltered and tied. All buckets must be hung chest level or higher, same with hay bags. Hay bags must be cotton and tied to baling twine. Halters must be breakaway or all leather - and worn at all times.
Trubandloki has a point about the teamwork – it really will impact final scores if everyone is doing their own thing and not aware of where other team mates are struggling. Make sure that everyone has a job and that they do it – it is not just the stable manager’s job to keep you guys on your toes. I remember that many of my team-mates would treat the stable manager as the groom that needed to do the grunt work. The only thing SMs are responsible for is knowing where the kits are and everyone’s schedule. They are not free labor.
I miss rallies so much. While they sound like a lot of work, they are great fun. Have a blast!!