Now that you've dreamed, designed, built, and tested your mod, how do you make it look professional? Also, how do you get it mass produced if you want to sell it?
Make your own PC boards!
Now, it's much easier than spending time drawing on boards or using photoetch techniques to design the board in some CAD software then ship it off to have it custom made.
First, download and install the EAGLE Light software from
http://www.cadsoftusa.com/download.htm. It's a free program for hobby use, or cheap to register for business use. It's not something that will break the bank and will do Schematics, Layout, and Autorouting functions. It's $49 to purchase and will do board sizes up to 100 x 80mm, perfect for most game mods.
Second, read up on the tutorials on SparkFun:
Getting started with Eagle PCB and schematic captureThe basics of laying out a PCB with Eagle How to create a custom footprint and part in Eagle PCB Once the schematic is drawn and the board layout is made upload it to the PC Board manufacturer of your choice. I used
http://www.batchpcb.com with good results. They charge $2.50 a square inch plus shipping and a per order processing fee of $10 (Check their website for current rates) In 2 to 4 weeks you'll have your PC boards back via FedEx.
Here's a picture of a 1" square board I designed for a composite video modification for the Colecovision game console. The assembled kit will be up for sale soon on my website.