Breeding in hand means you need only breed the mare once every two days so long as you get a good "cover".
I always have the mare tied up- someone holding her will not really work as she will want to move forward all the time and it takes very little to dislodge a stallion. So, you need somewhere safe and preferably padded.
Depending on the size of yours stallion and the size of the mares you also need somewhere with a small pit and railings!! (I have three under- well under- 30" so this is a must for me)
You will need to wrap the mares tail.
Now the hard bit- you need to teach your stallion to "tease"- a stallion that just leaps in and does the deed is a pain and can get everyone badly hurt, a lot of mare, even in full season, will not take a horse that behaves like this.
I used to use a stud chain on the Arabs, to remind them to mind their manners, but have never needed one on a Mini- I always use the same halter and i always breed in the same place, thus the stallion gets used to the idea- now I am going to a show, OK no breeding.
Now I am going to breed- Whoopee!!!
This way I do not get stallion "drawing" in the ring as they know they are not going to be breeding so it is a waste of time.
I also get up close to the mares head so I can grab her halter and give it a jerk if I think she is being naughty.
This also "keys" the stallion into knowing the mare is "ready" as I do not go to her head until he has teased her and we know she is standing.
So, if I do not go in, and she is squeaking, the chances are he is out of luck, and both mature stallions accept this.
The colt needs a bit more time as youngsters get over excited.
The five year old horse was really pushy and even a little aggressive at first but I just pushed him over and sat on him (Confucius say "Stallion standing right up on hind legs waving front feet at owner should remember he is STILL very small. Also horse on two legs is not as stable as horse with all feet firmly on ground"
: )
I hate running stallions out with the mares- I have far too many to be bale to get all the dates right, and the chances are that half of them will not get in foal this way, anyway- which is exactly what happened last year when I had to do it.
I find in hand covering the easiest and most accurate, but, if you have only one or two mares, once you are sure that your colt is doing the deed correctly and the mare is OK with it too, I see no harm in just leaving them together until the end of her season.