1) Add within pickup sounds
first, before you start adding mods that deal with combinations.
These include coil taps and series/parallel combinations when dealing with
humbuckers. One approach that addresses both is to use an on-on-on
toggle switch that will give you series/tapped/parallel
combinations for your humbucker.
2) Now you can begin to think about how
to combine pickups, so add in a phase switch
here if you want one.
3) Before you proceed to the pickup selectors,
do you want individual controls (e.g., volume and/or tone) on individual
pickups (i.e., like on a Les Paul) or just a master controls (i.e., like
on an typical Ibanez)? If you want individual controls, add them
in at this point where they only affect each pickup. After this point,
the entire output of the instrument will be affected by any controls you
4) At last, combinations! Add in
your pickup selector switch.
5) Now you can add in any "master" controls
such as a master volume, tone, varitone, and/or any preamps
or EQs you want applied to the whole system output.
6) If you have a piezo
bridge, this should enter the circuit at this penultimate stage.
Ideally you should connect your piezo to a three-way (i.e., Les Paul type)
switch so that you can either either your magnetic pickups, the piezo,
7) Finally, make sure everything is grounded
(don't forget the string ground if you have passive pickups!) and go out
to the output jack.
8) Rock out!