Obviously, you must like, and hopefully respect or come to respect, the person you choose as a trainer or coach because you will be spending a lot of time and money with this person. But, there are many other things to consider too which can make your time together much better.
Often, I see people attempting to seek help from professionals who have little or no experience or expertise in the area the person is interested in. In such a case, lasting results are rare and if you think about it, it really makes no sense for you to pay someone to "learn on the job" in the discipline you want to compete in or learn about.
To find a good match in a trainer or coach, you need to determine what your goals are. You need to be realistic. If you have an average horse and you don't have the money or inclination to purchase a higher quality horse, it's probably not a good idea to go to a trainer who's only interested in taking clients to Nationals or World. Reality is, that trainer will probably never bother to know your horse's name, much less ever throw a leg up on him - and hopefully, they'll tell you this outright before they take your money.
Training and teaching styles are definitely something to consider too. The methods used must suit not only you but also your horse. No trainer succeeds with all horses. You also need to think about what you're looking for personally. Do you want to improve and learn, reach a goal, improve in the show ring? Or, do you just want a safe hobby or maybe some social interaction? No coach or teacher is right for everyone. We all learn differently and we all teach differently. Barn atmospheres vary greatly too. Are you comfortable at the barn? Do you look forward to your time at the barn (you should!)? Are people too chatty, just wanting to talk when you want to ride or do they just want to ride and focus when you'd really like someone to talk to?
The trust factor is a very important component to consider. Can you trust the welfare of your horse with this person? Is he or she reliable? There are some very talented people who for many reasons might not be good stewards for your or your horse's safety and welfare. Are they too busy to help you when you get outside your comfort zone? If you are not advanced in your skills and knowledge, they might not be a good choice for you.
Lastly, training philosphies should make sense. Training is not "gobbledy gook" it must be based on sound fundamentals and techniques that take you and horse through steps and achieve results - no matter what your goal is. Hopefully I've given you some things to consider and, just like Goldilocks, you can find a trainer or coach, as well as a barn, that's "not too hot, not too cold, but just right!". See you next week! JD