Display Case/ Shadowbox

Assuming you've taken the time to CAD out a design and you've got your dimensions...
Hit the Hardware Store/ Lumber Yard or unguarded construction site.

1/2" x 2" & 5" x8' MDF Baseboard
1/4" Pegboard
LED Puck Lighting Kit
Wood glue
1 1/4" Nails
Hole Filler

Tools:
Table saw
Chop saw
Finish Nailer & Compressor
Tape Measure, Rafter's Square & Pencil

I ripped an approx 1/4" slot out of the 1/2 " x 5" MDF for the peg board to rest in.
Then cut my boards to build the frame.
(Looking back, I should have gone with 5/8 MDF or a 1/2 Plywood just for stability)

I went with a Primed MDF, easy to work with and pretty forgiving. I was painting it out to match the trim in the room so grain wasn't important.
That and this was kind of a quick and dirty job.

I painted the 1/2 trim first, then cut to size, then I tacked it in to place.
Before filling the nail holes, I test fitted one of the guitars I'll be displaying.
Fill, Sand & Paint...

This case is built into the wall, so I popped a few holes in the bottom board, routed out a slot to hide the wires.

I framed an opening for my display case, long before I planed this build, then built my unit to fit.
I ran electrical for the LEDs, finish that connection before anchoring the works to frame.

I used heat shrink tubing on the pegboard hangers to add a touch of grip and hopefully reduce any scratches to the guitars.