I'm not very active anymore, but I see that I still get nice people asking for permission before using my brushes or attributing work. So just to clear the air here, you're free to use the brushes and resources in whatever you want. There's no need for attribution (although, feel free to do so if you prefer). As for individual works, you may also use them for your needs. Attribution is encouraged on this part as it's not a free resource, but considering DA's extremely conservative approach to art theft nowadays, I can't really stop you if I'm not aware of it.
Good luck with your works!