Comment on Susiron's profile

Thank you for the apology, but please keep in mind that there is never a good reason to use someone's art without their permission and post it. Even if you credit them, this is stealing. If you ever want to practice by tracing something, it should never be posted online-- especially on an art site that puts your copyright onto any images you post (such as DA does). 

It's also worth mentioning that not all art online is unusable. Many artists do post artwork or photographs with the intentions of letting other people edit them. If you look under stock images on DA, you'll find many of these images. These artists will usually have rules regarding the fair use of their images in the descriptions.
Some artists will even let you use images that they don't have posted for stock-- as long as you ask them and get their permission-- and give them a chance to say no, if they so wish. Permission is the most important thing. Actual permission, since an uncoloured sketch is not permission.