I went to a upholstery place and bough some scraps of leather in a few colours. for like $30, now if i want to I can make about 4 gear boots out of this. Suede was even cheaper... but me wanted leather...
A must for this DIY is a sewing machine... apart from knowing how to use a sewing machine the rest it very very simple...
Requirements:
>> Sewing Machine, Threads & Basic Sewing Knowledge
>> Material (Can be anything, has to be thick)
>> 1 Cable tie
All you do is just take the original one out measure it out cut the materials and sew it together, then put the special ring in with a cable tie (from the original gear boot), and Voila...
Time:
Taking the original one out: 2mins
Measuring material: 10mins
Sewing: 30mins
Trimming & Fitting the new one in: 10mins
My first one is made in white leather, and it looks awsome. Can't put pictures up as atm don't have a camera...
All together, a very nice, and cheap gear boot.

Oh, and if you have a bored grandma... you can even get her to sew it...
