DuraCoating like any form of refinishing is mainly prep, prep, and more prep. Then comes experience. Just like any other skill set (with very rare exception) you are not going to get it perfect the first time.
My advice for a new person is to spend the money on a few airbrushes/HVLP guns and a compressor - stay away from the "compressed air in a can" setups you can get. These do not maintain proper flow and have a slew of other problems.
Second of all, degrease the parts very well. From this point forward never handle the parts without gloves. The smallest deposit of oil from your skin can ruin the adhesion in that one spot.
I will generally soak the part in a mix of hot water and TSP for about an hour then blow it dry with a compressor. Hitting in with some Acetone as a final step is good to.
Here are some other works I've done:
Ready for the nasty? lol
Thankfully it got better after visiting the Gun Hospital: