I used both the Doodlebug flock, which is the crushed velvet style. And I used Fun Flock, which is fuzzier. The Fun Flock does go on easier, you can rub it out more. I use the tweezers that come with the Making Memories tool kit to apply it. I would grab a bit of flock, and then dab it around, and then rub it out. The Doodlebug I definitely had to dab more times, and when I would rub it out, it wouldn't rub very far.
I'm guessing, applying the red over the black, is your problem. For the most part, I match the cardstock to the flock. So on the snowman, I printed the red hat band on red, and then applied red flock. Black/Black for the hat, Green/Green for the scarf, etc. and then put it together like a paper piecing. The exception is on the full-body monkey. That is printed on dark paper, and then I used the Doodlebug flock for the dark brown, and the fun flock for the lt brown parts. That one I had to do very carefully. I put the Doodlebug on first, and then the fun flock.
I prefer using the Fun Flock on animals, since I want the animals to be fuzzy, but the Doodlebug was great for the clothes on the Snowman.
Hope this helps!