I haven't built one yet, but I've been reading about them for a while now and would really like to give one of them a try, with some ongoing health problems, sometimes the stuff we use with plastic models really bothers, you can build the paper models with ordinary white glue.
I'm going through the boards, there are some paper modelers that are really hard-core believing you can only use the parts that come with the model and it has to be made with the printed material.
Then there are others that will build up parts into a really good 3-D, sanding them to shape and using filler as needed. Then they use a sealer on the paper and paint and weather just like you would a plastic model. They will also use bits of plastic rod and wire as needed. To me, the ones built this way are the best looking. When making parts that are curved like the front of a cowl of an airplane, they will be built in sections that angle a couple times. A lot leaves it like that and to me it looks terrible, others will use the back of a paint brush and burnish the paper until they get a beautiful curve, sometimes even compound curves into the paper, they work it until you would believe you are looking at a plastic part from a model.
A lot of the models I have looked at have a sawed tooth edge where you will glue on the next part, apparently it's the easier way, but you always have a ridge because one piece of paper is glued on top of another. Some cut those parts off and then cut some paper tabs and use that on the back so the parts can be butt joined which definitely looks better.
Some of the best paper modelers I've run across are on Polish and German boards, it's been way too long since high school German so I can't read either board, but they tend to put up a lot of photos so it's easy enough to follow.
I'll look through my favorites for some good builds.