My DIY switching pedals, these were some of my first builds and are an easy way to get into pedal building (they are pretty easy).
reverse order switcher:
This box does one thing, it reverses the order of two loops. Here is an example: Phaser in loop A (output of phaser into “loop A – in”, input of phaser from “loop A – out”), then hook up a fuzz pedal to loop B (same as phaser), the guitar signal goes into the switchers main input, and the main output goes to your amp. In one switch position the effect order will be guitar->phaser->fuzz->amp, and in the other switch position it goes “guitar->fuzz->phaser->amp. This creates a totally different sound with the same effects. I have even used it on groups of pedals (all my dirt pedals on loop A, and all my modulation (phase, flange, etc) on loop B.
A or B box (I added a second switch for A/B or C):
I use this as an easy way to switch between three different guitar preamps/sounds (clean/fuzz, blues, crunchy metal). It works quite well for this. Remember this is not a bypass box at all, it’s an “either/or” box.
I actually don’t have a layout for this, I will create my own if I cannot find one.
Bypass Looper with Volume control:
Mine has a feedback switch and feedback knob, but it’s not that great, If I built it again I would just do the single switch and single volume. Works really well with my Morely Power Wah as I can control the volume of the wah, and the true bypass is amazing compared to the bypass in the Morley.