I write down the clearance with my own shorthand that I know and that makes it easier for anyone. Practice listening to clearances and writing them down. When I fly in the real world I write down the clearance or a reroute enroute and that’s it. I have a few videos on IFR flying and clearances. Here is a video I did with a former air traffic controller. You can see what I wrote down when he gave me the clearance. It’s not much but it’s everything needed. Real ATC Communications in FS2020: A Tutorial - YouTube
But what it really takes is practice, practice, and more practice and knowing the format of what ATC will say and what you want to say back. It used to make me nervous but it’s not big deal now. And if they say something too fast and give a fix I don’t know, I ask them to repeat it and to spell the fix.