Here's some random advice.
Mother's seating: I have two nursing stations, one with a the most amazing couch with a detachable back so their feet dangle out into open space (the fireplace :-) but at night I use a regular an armchair augmented with a collection of pillows from other chairs and couches. I can only nurse in an armchair if I have someone to hand me the second baby and take them away again, but that's my usual situation. On the couch you can do the documented thing of picking them up from the couch beside you.
The EZ-2-Nurse Twins pillow is longer than others, so you can use it without augumentation for longer. Once they're taller, though, I needed something to push my butt forward on the chair to make room for their feet. So I have three pillows behind my back now that they're so large! Pretty soon I'll fall off the chair. I found the back support that came with the EZ-2-Nurse is too short -- I like my back supported all the way up. I took the back pillow from the EZ-2-Nurse and the back pillow from the Nurse-EZ pillow and sewed them together to make them tall enough to be useful. Then added one more couch side cushion, and a very silly thing I constructed from one of those cat scratching posts that hangs from a doorknob. (Hey, whatever works!)
Sometimes I nurse on the floor against a wall, and I need the same collection of back pillows so their legs have space. Outdoors I've dispensed with the pillows thusly: sit on the ground with a narrow tree behind me. It worked great :-) On the floor or ground I need a cushion on each side to use as tail support on the pillow or the weight of the baby pulls them down uncomfortably.
When I visit other people and plan to nurse both babies together while there, I look for a regular armchair. They usually come in pairs, so I grab the seat cushion off the other one and put it on my chosen chair. This raises up the seat to approximately the same height as the arms. Once I sit on the cushions, it's usually the correct height to support the tails of the pillow. Sometimes I need additional cushions if they're squishier and so I sink in too much.
At various times I tried things like a thin pillow above or below the EZ-2 to raise up the whole platform, or a footrest (in the form of a phone book) to raise my knees. These little things may make all the difference in your comfort and their abilities.
By 14 mos, 27 and 30 lbs, it got to be a bit of a stretch; at the armchair we employed end tables as sidecars to hold up their butts which otherwise hung off the side of the pillow. For the couch we have some other pillows for the sidecars.
Baby positioning: I can use the pillow in a mostly hands-free fashion, but my default "rest position" is with heads held. If I'm trying to do something else like eat dinner, I can briefly adjust heads if needed.
I have a clear plastic cookbook holder I put my book in, so I can read. Then I take it out, turn the page, put it back in, and have another two pages worth of time to worry about babies if needed. It's really a great thing.
When they were little, I used a receiving blanket on the back of their heads to keep them from rolling off. Some blankets are stiffer or softer than others and it matters what you use. I had a collection of blankets I used to stuff in corners below the breast and a baby mouth and also behind their heads to keep them from rolling off. I found the softest blankets were best for crumpling, and the stiff ones for folding and making little wedges.
Waist straps: The pillow comes in two versions, foam and inflatable. I preferred the foam one which I got after they were about 3 months old, but they're different in size and it may be that the inflatable is better for newborns. Not having used the foam for newborns I can't say for sure. The foam version has the strap in the back so you can cinch it tight. For the inflatable we added some straps on the sides to cinch it in -- so that there were three straps going around the pillow to wrap the waist strap, the center strap having been included with the pillow. This was necessary after they got to about 12-15 lbs. Just any old thing will work, you just have to tie it around the pillow and waist strap.
Photos: I have a page of photos of nursing my twins at different ages. Not too keen about having links to them on the internet, so if interested please email me (yduj@cs.stanford.edu) for the link.
My Twins: My partner maintains a site of pictures, news, and other information about my children. Check it out!