Well, there is a couple ways of doing it. You could make an auction or just sell it.
For an auction you usally put the price reasonably low so people an auction up the TC depending on how much the buyer wants it and how good it looks. and has an end date on which the texture has to be sold. Usally comes with an autobuy too, Ex).
Auctioning Head texture
(Picture)- Make sure you put it as a spinning globe(In GIMP) or take a few screenshots.
Starting Bid- Most likely a pretty low price so the bidders and Build up TC on it.
50TC
Mininium Raise- The least TC you can rasie when you bid. It has to be at least 10 TC or more
100TC
End date- Usally So many hours after last bid. Or a set date.
12 hours after last bid
Auto Buy- A Normal to alittle overpriced-
1.5k
Regular Selling, It's somewhat the same as Auctioning the head but has no end date.
You can have people offer how much they want to offer to get the head or you can give a set price they have to buy it from.
Hope this helped a bit.