Hey Bones, I had the same problem (for a very long time ). In the beginning alternate picking seemed the most fast way for me to pick two notes on one string. But after a while I realised that it didn't seem like "Gypsy" any more. I went back to playing all downstrokes, and eventually it really payed off. I think the key is that you have to focus more on your (loose) right hand and everytime you practice (slow in the beginning) being aware of the motion your hand makes. You have to avoid tension in your hand/wrist/arm. I also think you have to hold your pick very loose (not too much) to get it right. I'm not sure if it works for you, but it works for me. Good luck!