Since a lot of people seem to have trouble with either resizing or correctly uploading their skins (especially during a contest! ) I though I'd post a few tipps for those topics, to help people who want to participate in a contest or sell/trade their custom skins. I will go over multiple drawing programs and image hosting sites, as well as explain how to get the image from your deviantArt/furaffinity/whatever art site you're using into your post.
The version I am using is Photoshop CS3, but this is pretty much the same in every Photoshop version. I will also add PS Elements screenshots. The PS I am using is in german, so I added the translations for the important parts.
So you've finished drawing you awesome skin and want to upload it, but need to resize it. Here's how it works in Photoshop ( and it's really really simple):
1. Click on Image, then Image Size ( or simply press Alt+Ctrl+I )
2. Enter the new Image Size, make sure it's set to pixels (standard setting). For the skins this would be 350x350 px . This one looks the same in CS and Elements.
Tipp from Oszs:
And that's it! Now make sure to save this as a .png file ( File-> Save As -> Choose .png in the dropdown menu on the bottom)
1. Click on Image, then Image Size
I am using an older GIMP version, so the option might be at another position in the menu, just look for the right icon!
2. Enter the desired size (350x350px), make sure the chain item is a complete chain so that the proportions are right. Then simply click Resize!
Now save your image as a .png, by clicking on File -> Export and changing the file ending to .png
1. Go to Canvas and click on Change Resolution ( not size! )
2. Enter the new image size (350x350px), make sure the Constrain Proportions box is checked
Now just save the image as a .png file ( File -> Export -> .png )
If you already have a finished .png file, but it's not yet resized yet and you don't have access to a drawing program at that time, you can also resize your image online.
A good website for this is this one . I will show you what is important for correctly resizing your picture. In order for this to work, you must already have a .png file.
1. Upload your .png image
2. Choose the following options:
Width: 350 , Height: 350
Smoothly Interpolation: Check
Quality: Without Compression

Then simply click go and when asked, choose "Save File" (just like any other download).
Another website is this one, it's fairly easy to use
1. Upload your .png image and click on "Continue"
2. Scroll down to the "Resize Your Picture" Option, choose the following:
Dropdown menu: "Custom Size..." - > Width 350px, Height 350px
"Choose Special Effects" -> None
"Save As..." -> .PNG
I will go over correctly uploading your image in the next part of this thread.
I hope it's okay that I made this, I just wanted it to be a bit easier for people who want to enter contests but do not know how to resize/upload, since this seems to be quite a problem!
Resizing

Photoshop
The version I am using is Photoshop CS3, but this is pretty much the same in every Photoshop version. I will also add PS Elements screenshots. The PS I am using is in german, so I added the translations for the important parts.
So you've finished drawing you awesome skin and want to upload it, but need to resize it. Here's how it works in Photoshop ( and it's really really simple):
1. Click on Image, then Image Size ( or simply press Alt+Ctrl+I )
Photoshop CS3

Photoshop Elements 7

2. Enter the new Image Size, make sure it's set to pixels (standard setting). For the skins this would be 350x350 px . This one looks the same in CS and Elements.

Tipp from Oszs:
In PhotoShop Elements you can't resize your image unless your check the 'Resample Image' box in the Image Resize menu. Hope that's useful, it had me hung up for a while.
And that's it! Now make sure to save this as a .png file ( File-> Save As -> Choose .png in the dropdown menu on the bottom)

GIMP
1. Click on Image, then Image Size

I am using an older GIMP version, so the option might be at another position in the menu, just look for the right icon!
2. Enter the desired size (350x350px), make sure the chain item is a complete chain so that the proportions are right. Then simply click Resize!

Now save your image as a .png, by clicking on File -> Export and changing the file ending to .png


Paint Tool SAI
1. Go to Canvas and click on Change Resolution ( not size! )

2. Enter the new image size (350x350px), make sure the Constrain Proportions box is checked

Now just save the image as a .png file ( File -> Export -> .png )

Online Resizing
If you already have a finished .png file, but it's not yet resized yet and you don't have access to a drawing program at that time, you can also resize your image online.
A good website for this is this one . I will show you what is important for correctly resizing your picture. In order for this to work, you must already have a .png file.
1. Upload your .png image
2. Choose the following options:
Width: 350 , Height: 350
Smoothly Interpolation: Check
Quality: Without Compression

Then simply click go and when asked, choose "Save File" (just like any other download).
Another website is this one, it's fairly easy to use
1. Upload your .png image and click on "Continue"
2. Scroll down to the "Resize Your Picture" Option, choose the following:
Dropdown menu: "Custom Size..." - > Width 350px, Height 350px
"Choose Special Effects" -> None
"Save As..." -> .PNG

I will go over correctly uploading your image in the next part of this thread.
I hope it's okay that I made this, I just wanted it to be a bit easier for people who want to enter contests but do not know how to resize/upload, since this seems to be quite a problem!