To buy skins that you have created, or from other users in the Mint Mall, you need to first buy credits. Credits, like the Linden Dollar currency of Second Life, allows users on the site to buy and sell from each other without exchanging actual currency.
Credits can be purchased on the Mint Mall or My Skins pages. All credit purchases are handled securely through PayPal, and deeper discounts are given to larger credits purchases. Once the PayPal transaction is complete, your account will be credited and you will be able to purchase skins. All skins cost at least 100 credits, but users can make credits from the sale just by raising the price of any skin they make. Anything you charge above the 100 credit base price goes into your account upon the sale of your skin. Credits may only be used to purchase skins, and may not be redeemed for actual currency.
Making a skin in the SL Skin Mint
To create skins using the Skin Mint is free. Adjust the color, position, type and blur amount of your makeup settings to customize your skin and preview changes in real time on a 3D avatar mesh. Only female skins are available at this point.
When you're done editing your skin, select Export Skin From the slide-out menu. Skins you create are automatically listed in the Mint Mall and your "My Skins" page. You may edit the title, tags and price of your skins on your My Skins page.
Selling a skin or demo
To make credits off of your skin sales, you must raise the price of the skin above 100 credits. Anything above the base price will be credited to your account when one of your skins is purchased. Titling and tagging your skin with useful search terms (e.g., goth, tan, red, etc.) makes it more likely that your skins will be found by other users. Tags are limited to prevent spam, so use that space wisely!
If you want to download a skin you've made and sell it in world, that's okay too. Just don't sell skins that other users have created, if you see a skin you really love, you can use the Skin Mint to make one like it!
Buying a skin or demo
Buying a skin deducts the skin price from your account's credits. All demos are only 1 credit to purchase and are maked with scanlines and the Skin Mint logo to prevent the resale of demo skins in world. The markings were designed for you to still be able to see how the skin will appear on your avatar, as shown in the un-edited in-world snapshot shown below:
Downloading a skin or demo
Once you have purchased a skin, it will always be available for you to download from your My Skins page. That way, if you ever lose your Second Life account, or your skin image files, you can log in to your SL Skin Mint account and re-download the images.
You will need WinZip or WinRar to unzip the skin files to your computer. The skins are uniquely named with an id number, so for easy organization you can download every skin to the same location. Once you have downloaded the skin files to your computer, you are ready to upload them to Second Life and create a new custom skin.
Uploading images to Second Life
Once you have signed into your Second Life account, you can look to the top left of the screen to access the file menu.
File > Upload > Image
Upload the images one at a time, including the head, upper and lower images. Image uploads cost 10 Linden Dollars per image, so that's 30 L$ per skin uploaded (not including eyes). You can preview the images on the avatar mesh before uploading as shown below:
Making a skin in Second Life
Once you have uploaded your skin images to Second Life, you can apply them to a new skin. Open your inventory window (if you can't find your inventory window, go to the top menu bar and select View > Inventory or type Cmd+I). Now select Create > New Body Parts > New Skin as shown:
Create > New Body Parts > New Skin
Right click your newly created skin and select "Wear" then right click your avatar and select "Appearance" to edit your skin. Select the "Skin" tab on the left of the Appearance panel, and click one of the boxes marked Head, Upper or Lower "Tattoos." This is where you will select the texture that you uploaded earlier to apply it to the appropriate section of your avatar mesh.
With a little fine tuning of your mesh settings, you can adjust your avatar's features to best match your new skin, like final SL Skin Mint skin and eyes shown below: