CMOS diy eurorack help please

Hi there. I’m building some CMOS modules, to process Gate signals.
So far I’ve just built some gate generators/lfo’s. I have designs for Dividers, a random sequencer, gate to short circuit etc.
What protection should I be putting on my inputs and outputs? I’ve been using the 5v rail, and direct outs from the chips. I noticed that the 40106 oscillator gets temporarily interrupted when connecting a cable.
Any help/advice is much appreciated.