Topside with tongue depressor floor installed and painted.
Select your flooring for different shades of wood.Apply thin transparent washes of brownish-gray flat acrylic paint to the bare wood and let some grain show through.I use a paint called JoSonja acrylic mostly because I got into it when I was decorative bird carving.The color on the floorboards is nimbus gray with a touch of raw umber added.Paint individual boards before gluing to sub-floor to avoid glue spots. Draw guide lines on the plywood sub-floor as a guide for laying down your strip wood ,after you decide which direction the flooring will run.Sometimes running your floor boards at 45deg to the walls makes for a different look.

Courtesy of Ken Hamilton.

Here is a good example of how to do a simple framed structures.How much of the structure that you will require will be up to what you are planning to reveal.The floor? plus a side wall?back panel plus two sidewalls,maybe even a little of the roof structure?
This would be a good time to get out some cardboard or foam board and do a small mock-up of your ideas.I use foam board as it is easy to tack together using pins.I like to do mine to scale ,as then I can use the mock-up for measurements if I decide to go to a larger or smaller scale.
Once you have your mock-up done, you can start being a little creative as to how you want to position the objects relative to one another, always keeping in mind the point of view through your reveal.I sometimes take a small piece of cardboard and cut out a reveal in it and look around the mock-up,looking for the best angles.You can also take pics with your camera and then go to photoshop and play with it there making your own reveal and even framing it.
Fun stuff eh!

This is the way most of my structures are built.I start with foam board and draw on windows,doors etc.,then holding an Xacto # 11 blade at right angles I cut them out. (Save the cutouts in case you change your mind and want to re-glue them in.)
I then begin framing the wall with the straightest pieces of wood that I can find ,following the same methodology as if you where framing a 1:1 scale structure.
If you want a barnsiding type structure do not seal the wood and watch for excess glue stains.
In most cases for shadow boxes you will only be sheathing the interior walls.
Warning! when using foam board and unsealed wood ,warping can be a problem.Find a flat surface and weight the structure down flat with books,bricks etc.. overnight,when using any type of water based glue.

I changed my mind after putting this together and moved the garage door then glued and taped over the old opening.

Courtesy of Shep Paine.

Hi Guys! I know it has been awhile since I posted anything to this thread.
I have been very busy getting my aircraft dioramas ready for donation to the Canada Aviation Museum.The new part of the construction is to be finished in Feb of next year but my dioramas will need to be ready to go well before that ,as they will be doing the finishing for public presentation.The fourth and last large 1/16th scale aircraft diorama will only be finished in a year or two after that, then I plan to concentrate upon bread box size shadow boxes of various subjects.I am very anxious to really get into shadow boxes but my other commitments must come first.
Cheers! John.