At this stage in my life, I'd hate to think how many racks I've wired for audio, video, power and control but it would be hundreds.
THE essential ingredient is thinking about it and planning, well before you start actually wiring. You can do a very credible job first time if you are prepared to plan and to make custom cables.
Middle Atlantic* have a paper on cable management that should give some ideas on how to go about the 'doing' of it.
Things to consider:
- Will all items be fixed in place, ie can you slide out the rack or get to the wiring in the rear easily? This will determine whether you can loom and fix the cabling, or whether the loom will need to move.
- Will any wiring/looms need to move because they will be attached to a door or hinged panel? If so they will need to loomed in such a way that they are not kinked or stressed by the full range of movement. They will also likely need to be protected from rubbing on panel edges.
- How often do you change gear out? Most of the stuff I build will be in service without change for years, so we cable tie it all down tight. If you change things every other week, consideration should be given to flexibility of arrangement of the looms and velcro cable ties might be more appropriate.
- Layout of the signal and mains wiring. A good rule of thumb is to keep all signal wiring that crosses mains at 90* to reduce induction.
Another tip is to sketch it all out before starting to clarify what you're going to do. It doesn't need to be a mm accurate CAD drawing, and use different colours for different items, eg red for mains. Then install all the gear and start with one thing, eg mains wiring. Then move onto analogue audio etc.
If it's going to be a permanent install and you're going to custom wire it, then 'pre-loom'. Make some temporary fixing loops out of a bit of scrap wire etc and place these every couple of rack units along the path of the loom section making the loops large so you can thread all the cables through individually, one at a time. Thread each cable through them one at a time from point to point as required and leave some excess at each end. Mark each end of the cable for what it is. When all wiring is in place, remove the temporary fixing loops, neaten all the conductors into their final position, and cable tie the loom together and to the rack.
Now start working out the final lengths of each, snip to length and terminate. Use a meter to confirm that you have the markings correct and you are actually terminating the right conductor to the correct position. It's easy to make a mistake especially if all the wiring is one colour.
Take your time doing it, and realise it's going to take you much longer than you think first time.
Looming standard fixed length eg 1m cables is much more difficult to get neat especially if they are going to many locations, eg AVR to multiple amps and sources.
Mains wiring - get someone qualified to do it if you're actually terminating the conductors, not simply plugging them into a power strip. If you do do this DIY, and I
strongly advise against it unless you know what you're doing, get someone to check it and test before powering it up. It would be a damn nuisance to have made a neat rack that because you got something wrong and the chassis is live and you end up frying your ass.
* They also have a thermal management paper on the same page that should be read by anyone building an enclosed rack.