*Make sure you learn the traffic rules of the track before you get out there. Every track has different rules regarding the direction you are allowed to pony when the starting gates are up. Some trainers will have you “backtrack” the wrong way, others the right way, some don’t care. Some horses do better going one way or another, which is something you will just learn. USUALLY they will be calmer backtracking. It’s good you are working for only one trainer to start, so you will get to know his horses and their little quirks.
*ALWAYS EXPECT SOMETHING TO HAPPEN!! No matter how quiet the horse seems or how easy things are going, don’t ever relax to the point of getting sloppy. Don’t let your pony’s reins get too long, you want to be sure that you can stop or turn on a dime. Don’t relax your lead rope too much either.
*Ditto to keeping the horses head by your leg. Not only can they get away from you if they get too far in front or behind, but if they have too much “freedom” they can kick your pony. Seeing blood gushing from a cut vein on your pony because you let him get kicked is a horrible feeling!
*Be courteous when going by the starting gates. Make sure to look and see if there are horses inside. The gate crew will usually yell “BREAKING!” to let you know that they are going to pop them out. Get out of their way as soon as you can and make sure you have a good hold when those gates clang!
*You and your pony are the racehorses “body guards”. When passing another horse, especially on the path to the track, put your pony between your racehorse and the other racehorses. Ponied horses often are feeling good and have a little freedom and love to kick up their heels! You don’t want them kicking somebody else. Also be aware of inanimate objects and give them plenty of clearance on your racehorses side, in case he decides to jump into them.
*Sit deep and back a little in your seat and keep your heels down to keep yourself anchored in case the racehorse tries to pull you out of the saddle 
*WEAR GLOVES!!! EVERY TIME!
*Don’t be afraid to speak up if you feel a horse is unsafe to pony or you don’t feel comfortable taking them. You have every right not to, and it’s much better to speak up than to get you, a horse, or somebody else hurt.
*If ponying a horse with a lip chain, make sure the chain is looped back to itself on the offside so it is snug and won’t come off, which can be a HUGE mess!
*Sometimes a horse who is pulling hard will do better if you take ahold of the noseband on the halter and hold it lightly. Just watch you dont get your fingers stuck, or they can rip you right off the pony!
*Keep your reins and your rope tangle and loop free and organized. You’ll get better at handling them with practice.
*A couple tricks I have learned to handle emergency cases when the horse is pulling hard and about to get free…don’t get in a tug of war, and don’t be afraid to give a couple quick hard shanks to get their attention. You don’t EVER EVER want to tie the horse to your saddle horn, but you can do a half wrap around it. A few bumps against an unforgiving horn and the horse will often back off his pulling. Even putting your rope hand ON the saddle to brace it can help. Some horses feel the give and take of your arm and will try to take advantage of it. …If you have a chain that is attached over the nose and under the jaw, and the horse is being unruly, you can twist the chain until the slack is gone. Gets their attention and can prevent pulling…And if all else fails, and you can make a loop out of your rope, and put it over the horses nose, and hold the loop in place, loose around the horses nose. This is an extreme measure and you can lose a finger pretty easily if you aren’t careful.
*Watch stud colts! Some will try to bite or mount your pony!
*Every trainer and pony person has their own methods of how they want the chain. I prefer it to be over the nose and under the chin. I feel it gives you the most control. Some do under the jaw. Some will do it buckled to the other side of the halter. I REFUSE to pony like this, you have extremely limited control this way. I tell the groom/trainer to fix it or I won’t take the horse. I have always regretted it when I haven’t made them change it.
*Don’t be afraid to correct dangerous or unruly behaviour. You have to keep yourself safe as well.
*Sing or talk to your horses, some of them really seem to like it 
OK, I think I’m done LOL! Hope it helps and you have a great time!!