I have used some BAT46 to clamp signals to the rail, as inputs can only be max to 0.3V.
Things to keep in mind when using Schottky diodes for input protection are junction capacitance (pretty low in this case) and reverse leakage current, which in this case is going to be on the order of 0.1..3 uA, which may or may not be an issue, depending on the input and source impedances.
But i dont really know much about what you said.
Well it's a big topic. Take a look at e.g.
https://www.digikey.com.au/en/articles/protecting-inputs-in-digital-electronics which covers the basics. What they don't cover in this article is that when you clamp input signal to power rails, then the rails must be able to sink whatever extra current the extra voltage of the input signal is able to source, otherwise your rails voltage may rise above acceptable levels. Short spikes (such as ESD or turn-on/turn off transients, like in your case) can be absorbed by capacitors (which you are supposed to have on power rails anyway). For prolonged input overvoltage you need something that will begin sinking current as the voltage of the power rail raises above a certain level, which can be as simple as a single Zener diode (of the beefier ones, if necessary), or more involved, if you need e.g. higher precision.
Simulate it. This kind of stuff is easy to simulate with little frustration, as it doesn't require any models beyond basic SPICE primitives, except maybe Schottky diodes, but they can be found easily (unlike some ICs, but that's a different story). It requires a bit of learning, but it's a very rewarding experience. In the long run it will save you a lot of time. Remember, though, that simulation has its limits. But adding explicit elements for parasitic inductance, capacitance etc. can make those limits much wider :).