Even more than with single babies, be very careful of your back when carrying twins (because they grow twice as fast, there being two babies). I had a back injury from too much carrying. This got very long. I seem to have opinions.
Try a variety of wraps. We were incredibly lucky and had people give us a whole lot of slings as hand-me-downs (we caught the tail end of three different families' baby time). Babywearing groups can be great for trying things out.
When mine were very small, I used a single moby wrap, with both babies in it. I agree, it was a huge pain to tie it on, and it seemed like as soon as it was tied someone needed feeding. When they got a little bigger, I would wear them in separate mobies: wrap one moby and put it on and put the baby in, over to the side, then wrap the second moby over the first. Sounds absurd, but the babies felt less squished. This takes some time to do, but if they both need bouncing at the same time, it can be worth it.
My husband and I did a lot of going places together with two baby bjorns or two mei tais.
For going in and out of places, I often either put one baby in a carrier and carry the other (it's far more secure than just carrying both in arms) or put one in a bucket and one in the carrier (because then I can set one baby down and have a free hand). This is particularly good for coming in from the car or going to a doctor's appointment.
One baby in a carrier (usually a mei tai) and one in arms is a nice quick way to do things, but it's how I hurt my back.
It took a while before I could do a back carry, but now I sometimes wear two mei tais with one baby on my back and one on my front. (load the back baby first, then the front...and take care of where you put the ties) I can't get a baby into an ergo or boba on my back on my own (too fiddly) so that doesn't happen very often.
I also sometimes go out with one baby in a sling and the other in a (single) stroller. The single stroller was more maneuverable, and I had more access to the babies that way than if one were on my back. (it is tricky to take the sleeping baby from the sling and put her on top of the crying baby in the stroller, then get the stroller baby out from under and into the sling, but I have done it.)
In the beginning (the first six weeks) we often went out with both babies in a single pram (the lie-flat kind). It was really lovely to see them all snuggled up together, and it meant I could nurse (because even now I can't nurse two when we're out) and have somewhere for the other baby to be.
I can also, in a pinch, use pouch slings, one over each shoulder, but that's awkward enough that in those situations I will generally put one baby in a pouch (they're tiny and just live in the diaper bag) and carry the other: again, it's more secure than carrying two babies in arms.
