An advantage of building your own dungeon terrain is the flexibility in design, theme, and color scheme. You can readily construct terrain that fits your individual RPG campaign perfectly. Many times building your own terrain means you also build your own adventures. This leads to an interesting problem. You may have boxes of custom terrain, but you need to have a reference map to use in designing encounters as well as allowing quick setup during a game session. If you purchase pre-built terrain, it may also have digital mapping tools available. However, what do you do for your own pieces?
One of the fastest ways is to assemble terrain in advance and take photographs. This takes limited skill and works pretty well. However, sometimes photos are a bit washed out, at odd angles, or a bit unclear. It can be a challenge to get good and direct top-down photos.
If you have a modicum of skill with digital graphics programs like Adobe Photoshop, Paint Shop Pro, or even Paint, you can create your own electronic tiles to represent each of your custom pieces. It takes a bit of time, but you can craft a fine mapping set that is very reusable and can clearly allow the Game Master to prep encounters and players to help with terrain setup during the game. Anything that allows the players to help with setup and save transition time can increase your game play time!
The above image shows a comparison of a digital tile next to an actual photograph of a floor tile. The digital tile has clean right angles and consistent color and shading. The photos may distort due to angles of the lens, lighting, or position of the floor tile.
The top image shows a section of dungeon that was pre-assembled and photographed. This could be used to map out the encounter and have players assemble, but notice some sections are a bit difficult to tell what wall pieces are used. The lower image is the exact same layout using digital tiles. It is more obvious which are the same wall pieces, and the heavier black lines make it clear which size floor tiles were assembled. It can be determined from the photo, but to me it is trickier.
Another advantage of the digital tiles is the GM can assemble in advance at leisure when designing encounters. Photos require assembling the setup first. This is a better solution for the GM on-the-go.
Digital tiles do not have to be perfect or exact. They just need to clearly represent the physical terrain piece. With a little practice and experimentation, you can create tiles that look polished and professional. If you make a set of tiles with no color or texture and another set colorized, you can reuse the no color tiles later if you build another set of terrain in a different theme.