Aa, pixiv is a bit tricky, isn't it? I've been a member with them for 7 or 8 years. It's a great community, I love the image response events! I had only been on for a few months when スジャータ was doing a little promotional and everyone was making their own personifications of Sujata-chan. It was awesome to participate in, it's definitely how I made my friends over there. And fanart is always good for garnering viewership, nothing wrong with a little fanart! I even found an incredible needlefelt artist hikaru to do art trades and stuff with. She's awesome! I just PM'd her about her work and we started talking!
My most rated and commented submissions are my ink free textures. I've reached the 1000+ bookmark status with them and I've gotten tons of great feedback. Plus, they get image responses which it's so much fun to see how people use my watercolour and Chinese ink splashes in their work!