Diorama

I've done both. It is probably best to glue them on because every time you bump or move the diorama they fall down and go boom. But, never be in too big of a hurry to glue down, I built a diorma and spent a year deciding the placement of all the figures on it. then I finally committed myself

I make little GI Joe type plastic feet things for them. i glue them to that then i place them on the diorama taking care to cover it in grass or sand.

I use white glue to stick the model :)

I drill the holes in the bottom of one or both feet prior to assembly and painting of figures. Wire of varioius guages (depending on the size of the figure) is inserted into these holes, glued and left fairly long. This helps to keep them "fingers free" while painting and makes it easier to handle. Or mount to a painting base. When ready for mounting I clip the wires to about 1/2" and they then become mounting prong(s) for the diorama or display base. Because the wire is thin (no thicker than the larger paperclips or 14 guage) they need only small holes. If you are not sure about placement, you can leave them unglued till you are sure. Otherwise white glue them in place. If you move the figure you have only to fill a hole the size of the wire. Almost always an invisible repair. This also works for some vehicle components or design elements of the diorama (trees, ruins, walls, etc.)

Mike