I am looking for a best practices USB 2.0 reference design

[Blitzschnitzel]

Hi,
I am designing keyboards and for most designs I need a custom PCB. I don’t have much understanding of electronics but most of the time I am just adding switches to an Atmega32U4, so it is relatively simple.
However, what puzzles me is how to best implement protection to the USB lanes. So far, I am just adding an USBLC6-2SC6 ESD chip and two 22ohm resistors between the MCU and USB-C port. When I look at other designs, I often see a wide variety of capacitors, polyfuses, ferrite beads, TVS diodes and of course different ESD chips.
Is there a good reference design with widely available components that I can copy? Or is there maybe even an IC that combines all this?

[Blitzschnitzel]

Even the manufacturer's best practice guides vary strongly. I don't know which components are important and which are esoteric fine tuning.

[Renate]

It seems to me the biggest difference is whether the USB PHY needs external build-out resistors (like the ATMega32u4) or not.
After that it's your choice to throw on an ESD chip.

... most of the time I am just adding switches ...

Some consideration should be applied to this too.
Using just the internal pullups on external switches doesn't cut it in my book.
I like to see some actual current through a switch, a mA or two.
You can throw a small cap on it too.

[Blitzschnitzel]

OK thx.
The switches are actually in a multiplexed matrix, so pullups are not needed.

[Renate]

The switches are actually in a multiplexed matrix, so pullups are not needed.

Mmm, I question that.
Take the simplest case: one output pin of the µC feeding to a single switch feeding to one input pin of the µC.
You're still relying on the internal pullup of the input pin.
That means it has an effective impedance of somewhere around 70k.
Try running your vacuum cleaner around that and you may get some surprising results.