I'll be adding more lineart as I colour various pictures so keep coming back!
1. Ensure that it is coloured differently in some way to the original.
2. Say on the picture somewhere, such as a disclaimer bar below the picture, that the picture was done for practise/educational purposes only .
3. Give full credit clearly to the original artist on the picture
4. Try to gain formal permission to post the picture - difficult when 90% of the time the email addy for the original artist doesn't work, they never answer back, or you don't even know it in the first place so that's why I'm saying TRY here.
5. Not sell or make any money directly from the use of said picture.
I might add some of the files are pretty big, so be patient, especially if you're on dialup.