• So guys how do you sell textures and show the picture

Look for the guidelines, tutorials and FAQs.

Questions shouldn't be posted in this forum too.

You will need to make a thread for the texture you are selling with the [S] or [A] tag in the title.
Upload a picture of the texture on your Tori or a spinning globe preview done in GIMP and post.

You can send a pick through manage attachments and find and select ur texture or through if ur selling it in a thread make a spoiler with the pick on there or take screens also put

Artist:Me (if u did it)

Size: (128 and so on)

Previous owner :Me ( or some one else who had it before you)

Min price: 25k or more

Additional

Best force lax to use: hunter relax pure force

And so on just be creative!!

First,you must and have upload the picture of the Texture. You can use manage attachment as yoyomagg said to upload the picture. Or you can use some program to upload picture like Photobucket,Tinypic,Imageshack,and many more.

Before you sell the texture,you must read the rules how to sell textures in Market Rules
Make sure you follow all the rules. If you broke it,probably you'll get a warn from Market Squad. You can use yoyomagg form to give the information about the head or maybe free form(i'm not sure).
If you have a deal,you can get the tcs by selling that texture.
Oh and watch out. In here,there's many free textures. You can't sell free textures because its illegal. You can get banned if you're trying to sell them.

Thanks Guys
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Another question How do you make a spinning Globe

Go into gimp (its free, you can create textures too,) make your texture and go to filters, there, there should be a pack that says "animations" scroll down a look for the "spinning globe" make a .gif o' dat badboy and post it.