Okay the ribbon I used in the pony above is pretty thick, you will most likely use a smaller width ribbon but it's up to you. In the "old days" they used to use thicker ribbon but nowadays I think they use a more refined ribbon. I also like to reuse my ribbons so the heavier ribbon is more sturdy. If I showed beyond local shows I might be more motivated to just get different ribbon
You can also put the ribbon in your AMHR Pleasure Driving horses, not only Roadster!
You will want to choose either two or three colors, in your Farm Colors (which should match your roadster silks, I'd imagine). The ribbons in the pony above are dark purple, lavender, and ivory. It is a simple three-strand braid, so you will either have three colors, or two of one color and the third will be the contrasting color.
First, braid the mane. You only get a TINY amount of hair to braid in, right behind the bridle path. If you don't have strong fingers you can use surgical forcepts to hold the braid and hair together. I like to tie all my ribbons together with a knot, finish the ends (fold the ribbon in half and cut at a diagonal, to make a "V" that sticks up) of each ribbon. Then I braid in the hair. At the end you can either tie the ribbon off or use a little mane rubber band. Then the bottom ends of each ribbon will be again cut in a "V".
The length of your mane ribbons will depend on the length of your horse's mane. The longer the mane, the longer your ribbon will be. Remember that when you braid, the braid will shrink up the length of your ribbon so cut it a little longer than you need. You will want the ribbon to fall in a natural position at the length of the mane; the pony above has a pretty short mane so imagine if that braid was even longer!
Your forelock, the entire forelock will be braided into your ribbons in the same method I have described above. It should be about the same length as the mane ribbon, maybe a little shorter if you have a particularly long mane.
I hope that helps any,
Andrea