I have been using mine for a little over a month, and I love it. Best decision I've made for my program.
I only have a couple tips. First off, go slow. You may be over zealous at the start, but be gentle. You don't want bruising, or broken capillaries. Time is what it takes for NBE, so don't rush.
Also, use heat. Before and after. Heat is your friend. It helps you get circulation going.
If you'd like to (I stopped within a couple days because the messy glue) but you can tape your nipples down to decrease chances of stretching them.
I had troubles maneuvering the cups in the beginning so I didn't lose Suction while putting them on one at a time. I used a bag saver clip to hold off one of the tubes while I put the opposite on.
Also, if you have trouble keeping them on because they're too far apart, or too low, use something to tie them together. I have my robe closure tie that I've knotted. I put it over my neck and drape it down, I then put my cups on in the loop that I've tied. It holds them close, I get great Suction, and they're higher on my chest.
I pump for about an hour and a half a day. I used evening primrose. Oil for the longest time, but I'm switching back to flaxseed.
Don't ever be upset either if your swelling isn't significant off the bat, or it doesn't stay for long periods of time. That doesn't matter. Keep your head and heart in the right place, and always believe in yourself. Your mind is your most powerful NBE tool.
Oh, and stay very hydrated!