I found a 48" square window screen kit and a roll of 48" screen material at my local hardware store, so that's the size I went with for my selfie spot. This is a pretty good size for a one-person selfie. The great thing about these screen kits is that you can size them up or down really easily, so measure your space and pick your size accordingly.

Be sure to grab one of the screen installation tools as well. It will make your life easier!

Even though my frame was 48x48, and my screen material roll was 48" wide, I still needed to trim 1" off my frame, because installation requires a bit of overlap with the frame and the 48" screen fabric didn't quite reach. Use a hack saw or a chop saw or whatever you have to get a clean cut.

The corner pieces pop into the corners in a most satisfying way.

Use a flat head screwdriver to pry out the foam rubber spline in the frame's groove. Pull it out completely and set it aside. 

Cut your screen to size, leaving about 1" overlap on all 4 sides. I found it helpful to clamp it on all 4 corners.

Use the convex side of your screen tool to tuck the edge of the screen into the groove. Place the foam rubber spline on top and use the concave side to firmly push the spline down over the screen.

Take your time and try to get nice even tension on the screen the whole way around. Trim off any excess screen sticking out of the groove.

Once you have your idea sketched out, it's time to lay it out so it fits as nicely as possible with your neon strips to minimize cutting and soldering. 

Cut a 1m piece of string for each of your neon strips. Use different colors to mimic the colors of the strips. 

Print out or draw any shapes or symbols you want to incorporate. Size them up or down on your computer before printing until the outline of your shape is the same length as your string (i.e. 1 meter long). I didn't do any math here, just a bit of trial-and-error until I got it right.

I really recommend not skipping this step. You'll be surprised how hard it is to get an evenly laid out star shape if you're working freehand.

Use the rest of your strings and some scotch tape to lay out your entire design. If you're going to cut your neon into shorter strips, you can mimic that with your strings as well. 

Pay attention to where the wired ends of the neon will lay out. It will make your life easier if you can cluster all the wires as close together as possible.

Before you commit to your final design, test it out by taking some selfies in front of it. Make sure your head doesn't block the main part of the design and that it's big enough to see when you're standing in front of it.

Flip your screen over so the strings are on the back side, and place the neon right on top. Cut a small piece of craft wire and use it to wire the end of your neon into the screen. Twist the wires on the other side to secure it.

Place a wire at all the corners and any place you feel it needs structure. I found it helpful to use an angled wire to add tension to the ends of the neon, to keep the corners sharper and the shapes more accurate.

When adding shapes, try to lay them out so the wired ends of the neon are as close to each other as possible on the back. This will minimize the amount of cleanup you will need to do later on.

Poke all the neon wires through to the back of your sign. If you've got a soldering iron, put it to use splicing extra lengths of wire between the neon strips. Your wires will show through so be as tidy as you can. It's very possible to hide all the wires behind the neon strips with a little extra wire and effort, if you want it to be perfect.

Use screw terminals at the end of your wires - red to + and black to -. I got mine wired so I only needed one screw terminal, but if you get a handful of them and some power cord splitters, you can use one for each neon strip to make this a no-solder project.

Wire the screw terminal to the screen for strain relief. These wires can pull out pretty easily if they're tugged on too hard.

Plug it in and watch it glow! 

If one of your strips isn't working, try reconnecting the screw terminal. These things are notoriously fiddly!