Thanks folks for your comments. Happy to let you know as much as I do Roland. They take around 4-5 hours to make and so I really could not sell them and keep everything fair, but there is a large amount of satisfaction once a watch repair/service is done and in the making one of these.
There is a lot of subtlety to making them as I am sure those of you who have done this will agree.
Firstly examine the watch, you need to evaluate the lugs carefully. How thick are they, what is the distance from the hole to the case. These are factors that need to be considered for thickness of the bands leather. You need to use strong leather that will last. I tend to use kid leather for the lining, suede side out as this is very comfortable. I also use leather for padding if I need to.
Consider stiching colour and length of the band. Try to get the buckle to lie on exactly the opposite side to the watch once the band is on your wrist.
I have made up some simple templates for the bands depending on lug width. You may have a lot of tools already, but these are readily available and cheap from eBay etc. In my view the glue is critical as you need the band to be flexible, so I use Japanese Seiwa glue. It has a long shelf life, dries at the right rate remains flexible and locks on.
For a long time I used a hand awl for the stiching holes, but now use the prongs you can get from eBay. Get a 10 and a 2 one. You will need the small one for curves.
Think how you use the leather, I try to get matching patterns for both sides, if it has these. I use scalpels rather than knives etc. These are just my ideas, the rest you will pick up easy enough. You sure won't have any problem with Christmas presents...In my view nothing sets off an old watch like the band.
Here are a couple more. I like the orange ostrich, but I think I am alone here. And thanks again for the kind words.