Among other folders, don't forget to reset Adobe folder permissions after every major new version of either Premiere Pro or macOS as part of routine maintenance.
The preferences folder is sometimes accidentally reset to Read Only permissions, rather than Read/Write. Reset the folder to Read/Write to restore functionality.
Read only folder permissions can be a source of unexpected crashing and general instability.
It is very important to maintain Adobe folder permissions for your macOS system and your own sanity. Make it a habit.
Make sure your media lies on a high speed drive connected via a high speed connection (USB 3 or Thunderbolt) that is separate from your macOS drive. This offloads a lot of processing within your system and provides better performance.
Thanks, these are great suggestions. Here's something you might consider adding to your FAQ. I provide support for a number of clients who work in Premiere and it's amazing how many ignore this sort of thing.
Make sure you have sufficient free hard space on all your drives. From what I've read, keep at least 20% free space on your startup drive and 10% on all other drives. Unless you have a utility that monitors free drive space, you should check this on a regular basis. It's very easy for some app to be saving large files to an unexpected location...