I currently have 208 DIY custom length cords. My setup is different from others here as I keep all my controllers in two custom made plywood boxes that I put on the garage roof (for security and vandalism purposes as I have two schoolbus stops in front of my house). Then I run the extension cords out from one central location. I have bundled the cords together based on location of props (beginning of light strings) and the controller that they come from. Each bundle is numbered and I have marked the bundle number the underside of the eaves the near the cuphooks that hold the bundles along the path the cords will hang. Each bundle is held together with Velcro onewraps about every two-three feet. This allows me to easily replace cords (which I have not had to do), reuse the Velcro, and the cords can slide as needed to connect to controllers/lights and make turns/bends. Number of cords per bundle is 8-16. Each cord is labeled on each plug end using a label maker and metallic label tape. The male plug ends have the controller ID (1-1, 1-12, 10-4, etc) on it, and the female end has a light string code (Left RE-R, Left RE-Grn, LW-Blue, etc) so I can easily locate, run and plug in each bundle of cords quickly. All of my lights are bundled similarly. Each color of light strings around a particular prop, say a window, are bundled together with their plugs labeled the same as the female ext cord bundles (Left RE-R, Left RE-Grn, LW-Blue, etc). Just match the plugs together and connect them. I can have my entire display up by myself in about 4-5 days depending on how energetic I am for that day. I store everything all bundled up as well. When I pull the display out for the season, I know where each light string bundle and ext cord bundle goes and hang them as a group and not individual strings or cords. Diagrams, spreadsheets and pictures are all helpful. As my display is very compact on a two story house and not spread out over a large area, this system works for me.