I've said this before, but I think it bears repeating: The control panel is probably the single most important part of your cabinet. It's your personal "interface" to the games that you're playing, so you'll want to make sure that it's comfortable, that it makes sense logically, and that it's intuitive to use. Of course, if you can pull all of this off while making it look attractive too, that'd be nice. :)
There are a few basic schools of thought that most people adhere to when it comes to designing control panels:
These people are usually only interested in playing a handful of very specific games, so they tailor their control panel for these games. If you know that you only want to be able to play 4-way games that require a maximum of two buttons per player, then what's the point in littering your control panel with a bunch of controls that you know you'll never use?
The biggest potential flaw with this approach is that if you later on decide that you want a trackball or additional buttons or any other additional control, you might have to re-do your whole panel.
A few people have decided on this approach because having multiple custom-made control panels allows for a great deal of flexibility while maintaining visual attractiveness and a more "authentic" look and feel.
I personally didn't go this route, because while the control panels look and probably feel very good, it adds a level of complexity that I just didn't want. The basic gist of either of these approaches is that if you require a control that's on one of the panels other than the one that you're currently using, you'll have to stop what you're doing while you swap or rotate the panels. And even if it only takes you 30 seconds to swap/rotate the panels, it just seems to me like it would completely yank you completely out of "gamer" mode and jam you into "cabinet maintenance" mode. I would rather have whatever controls that I want to use right at hand, ready to play.
This is the method of having every control that you want on one dedicated panel. The advantage of this method is that every control that you want is right there on hand, ready to be used.
The biggest disadvantage of going this route is that it's easy to end up with a "frankenpanel": a control panel that's so littered with multiple controls scattered all over the place that it looks like a bomb exploded at the Happ Controls factory and the fragments landed on your control panel.
Of course, bear in mind that I'm not knocking any of these approaches or claiming that any of them are universally better than any of the others. The whole point that I'm trying to make is that all of these approaches have some kind of trade-off, and it's up to you to decide what's important to you.
For me, doing an all-in-one panel made the most sense. I definitely wanted to be able to have a bunch of different controls, but I didn't want to have to deal with swapping or rotating out panels - I wanted immediate access to everything at all times. The big trick then is to figure out a way to have all of the controls that I wanted on one panel without it looking like a cluttered mess. I first listed all of the controls that I'd want to have on the panel:
I also had the following layout requirements for the panel:
And of course, - taking all of the controls and all of the requirements for the controls into consideration - I wanted the control panel to have an intuitive flow to it. In other words, I wanted everything to make sense, not only in looks, but in placement and feel. And I wanted everything to make sense not only just for me, but for anyone else who might walk up to the cabinet and play on it. Also, despite the very large variety of controls on the control panel, I wanted it to look as clean and neat as possible. I didn't want it to look like a "frankenpanel".
So once all that was decided on, it was then just a matter of playing around with the layout in Visio until I was happy with the results. I feel that I was able to satisfy every requirement that I had while still keeping it from looking too cluttered (in my opinion anyway), so I'm very happy with it.