Configuring the screens
Now that everything we need is inserted into the game, let's set up the screens. This section expects that you already have the parts for your screens placed where you want them to be.
Renaming screen parts
Make sure to name your screen parts so we can find them later using code. To rename them, select them in the Explorer window and press F2 on your keyboard. Then insert a new name like Screen1
Adding GUIs / Textures
First, insert SurfaceGuis or Textures into your screen parts. To insert them, hover over the screen part in the Explorer window and click the (+) sign. Then select either SurfaceGui or Texture in the popup.
SurfaceGuis should go into normal parts (blocks/bricks), Textures should go into meshes, cylinders, spheres, unions, etc.
Changing GUI / Texture properties
We are not done yet. We have a GUI (or a texture) inserted into the part, but it might be facing in the wrong direction. To fix that, select the GUI / Texture and go to the Properties window (View -> Properties if you don't have it open). In the window scroll down to the Face property and change it until you can see a small blue (or orange for textures) outline on the side of your screen that's supposed to be the front.
If you're using GUIs, it's a good idea to set the LightInfluence property right below the Face property to 0. This will make the GUI visible when it's dark.
If you're using Textures, you can set the Color property to something really high (like 2000, 2000, 2000) to make the texture glow. Higher numbers will make the texture glow more intensely.