If you have never made folders for your go-to plugins in REAPER, I highly recommend spending a few minutes setting this up. It has improved my mixing workflow immensely!
Here’s how my plugin folders look. It’s all organized by categories and I only added plugins I always use. I also tried to limit myself to just a few plugins.

I took some time to mindfully reflect on what are my go-to plugins. Having lots of options only slowed me down by a lot when mixing. I kept getting distracted into trying new things and it’d always break my flow.
Just having my favorite plugins organized by categories took a lot of the guessing game and made my workflow much more straight-forward.
Instead of trying to remember which are my go-to compressors, I just put them all in a Compressors folder. And now any time I need a compressor, I can see all my options in there.
I also like to throw in plugins that I eventually wanna try, which is helpful cause otherwise i’d forget they exist!
How to set it up
Open FX browser (Shift + F) and right click anywhere on an empty field of the left side and select Add folder.

You can drag and drop plugins into this folder or right click on them and select Add to folder .
Additionally, I like to add little separators for different groups of plugins. I do this by simply creating a folder and naming it something like ––– MIXING ––– or ––– GUITAR ––– .

Another cool thing!
If you right click the FX button in your track or anywhere in an empty FX slot in your mixer, you will have quick access to all your custom folders.

Video
I made a short video about this, in case it helps: https://www.youtube.com/shorts/QNzb0iWnP0Q