This is a player screen I made for the Medina game pieces at:
http://www.thingiverse.com/thing:943076

The roof and walls use 3 magnets each (0.8mm diameter, 1mm thick) to attach right now. I really like the magnetic attachment, but feel free to modify it for a peg or something if you prefer. You don't even need to glue them in place, I just put some ABS slurry over the top and when it dries it leaves the magnet under a very thin coat of abs.

The hinges on the walls are print in place. If you have problems with the inner hinge not sticking to the bed enough, try printing it with a brim. This will lock the lower layer of the hinge in place, but you can cut it out pretty easily with an exacto knife (see the two before and after underside shots).

The hinges on the roof are made to take a 3 mm piece of printer filament. I just cut a piece to size and then heat up a knife in a candle to melt the ends of the filament so it does not slip out of place. Some small bolts/screws would surely work fine as well if you don't have this size filament.

I have printed this in both ABS and HIPs. I would suggest ABS personally as it is super easy to fix any splitting with some ABS+acetone slurry. For the least amount of splitting on the main wall, Print the ABS hot (for esun brand I used about 270 C) and turn off the cooling fan to maximize layer adhesion. There are no tricky overhangs to worry about.

This was sized and made the way it was to fit on the bed of a Lulzbot Mini, which is just about 6 inch square.