How to find and chose a good driving horse
Look, observe and take advice before making any decisions.
As a novice you really are best advised to elicit the support of your Driving Instructor. They will be able to honestly assess your competence and experience and help you to find a pony or horse to match your ability.
Think carefully about the breed
Remember you make haste slowly - even if your ultimate aim is to drive hackneys in the show ring or a sports horse in CDE, these are not the horses to start with. It would be like driving a ferrari or a formula 1 before you'd mastered the technique of steering.
Your first driving horse might be plain but it's a fact that a flashy, showy one is ALWAYS harder to drive than a plainer, more even-tempered one.
It's the very high-spirited nature that dictates this and you will find the more spirited and able to think for himself that your horse is that the faster, surer and more automatic your reactions need to be. Something that ONLY comes with miles on the clock and testing yourself properly over time and with good help and lessons.
If starting with a family pony, get someone experienced to put it to harness for you.
For anyone not genuinely experienced with putting a horse to harness and bringing on a youngster, I'd say never less than 6.
If buying a new horse or pony, think CAREFULLY what you want to do with it I.e. Will it be ridden as well as driven. That will determine the size.
How heavy are you? What sort of terrain will you be driving over? What sort of vehicle will you be driving? Again all determine the size and strength required.
You'll struggle to look past any of the traditional native British pony breeds for a good all-purpose driving horse:
Any of the welsh ponies and of course the section D are up to weight for the largest adult and all make terrific driving ponies and are up to the job but the welsh D or cob type are a little larger. Also useful enough to ride and drive are: Highland, Connemara, New Forest, Dartmoor.
The American Morgan makes a darned decent ride and drive horse too.
Be honest and use a liberal dose of self-awareness when it comes to assessing your own ability and competence. Remember experience is just time spent. Competence is entirely different!
As a novice, buy a horse that has been well trained and tested as a carriage horse and that REALLY knows it's job. It should be 110% traffic proof. It should want to stand forever unless it's been told to go forward and it should know how to look after itself at all costs.
The overall turnout of horse, vehicle, driver and passenger should look balanced and in harmony. Be neither under or over-horsed: neither in size, type nor ability.
Ensure you have public liability insurance before driving out on roads
Two novices are NEVER good mix
You and your horse can't "learn the job together". Most frequently that ends in disaster. And yes, you'll hear people telling you it can be done but in my considerable experience, it can't!
Green + Green = Black and Blue