This is very much a case of do as I say rather than do as I do ... I'm very guilty of buying gadgets that I end up not using much. I am currently building a smaller board that I will occasionally connect to the larger 'gadget' board when I want to play with toys and come up with more adventurous textures.
Basically the stuff on my main board will be the tuner, a Boss NS-2, a MXR M-80 D.I. (for when I use it with my bass) and then my effects loop (which besides the EQ and ISP includes my flanger, chorus, and delay running through a Boss LS-2 (to mix in some dry signal) followed last of all by a clean boost. These seem to be the ones that are either on all the time or are two inconvenient to split over two board (i.e., the effects loop pedals). The second board with consist of a wah, volume pedal, and two front end loops (again via a LS-2) connected to the first board via the loop on the NS-2. I know this sounds ridiculously complex but it is a good way for me to keep the toys (which are mainly front end pedals) separated from my main rig so that I am not taking thousands of dollars worth of stuff to shows where I don't need them. I may well use the two boards live if I start up a funeral doom band but it would have to be something slow like that for me to find time to use them all. I can also put bigger pedals on it or pull stuff on or off without upsetting my main gigging board. There are three 18V pedals on my main board (EQ, flanger, boost).
I haven't finished the smaller board yet - I've had really bad luck lately with sellers online, including a shortage of velcro for the two pedaltrain products I bought from different suppliers (the Pedaltrain Jr and the Universal Bracket kit) - but this should be the layout:

I can't imagine using more than this on a regular basis. The other guitarist in our band uses wah; no point in both of us using it. Of course I had to buy a second power supply (a Fuel Tank Junior), so it all gets rather expensive.