I come from a studio background so an aquarium is fairly simple. First, never wrap wires together unless it's a system. For example, if you have two lights, you can wrap them in some cable wrap/wire loom, same with a heater and temp probe but if it isn't a system, don't bother, it will bother you more by doing so. Use power strips for systems. I only use two, one for lighting and CO2, the other for my filter, heater and UV. That way you turn off the right thing while doing a water change or maintenance, but you still have the systems you want on while doing so. You may not care to have the CO2 on during the water change, but, your timer may reset or get off if it's mechanical so it's worth doing, IMO.
Wire tie, velco wire strip is very nice. I use this for wires that are really long. At one point, I think I had about 90% of the stand taken up when I had autodosing, inline heater, UV, etc. Make sure you can get to everything without ripping everything out, enough slack to move anything that is in front of something else, try to make it so you don't need to move stuff. Now my tank follow more of the KISS method so way less wiring.
The only thing I struggle with is a place for my dry ferts. I have plenty of room in the stand, just not at the bottom. I may make a little drawer up top for my every day things that are not powered or something.