When mixing it's crucial to keep track of different material in your DAW to be able to quickly address problems you notice. The last thing you want is looking through poorly named tracks to do some EQuing or compression, finally realizing that the drum sound you where looking for was named like Audio_0123; totally unrelated to the audio material. To keep track of the material I therefore rename tracks in the preparation process. I have a system for this that I use all the time but this is totally up to you. Just pick something that works and stick to it. There are some ground rules though that could help a lot.
I'm from Sweden and our alphabet contains some characters that isn't in the English alphabet. The problem with this in the digital world is that these can translate to super weird names in a DAW, especially if the files where compressed using a zip/archive software. A letter like Ä can easily become ^£¤^ in the translation which of course isn't what we want. Therefore I stick to English names for everything even though that's not my first language. Long names can also get cluttered in a project. I therefore shorten all names so I can see them without having to expand my tracks. For instance Drums can be renamed to Drm and Guitar can become Gtr. A lot of DAWs also add numbers and other things to the end of the name to keep track of things internally. A track from Pro Tools might have cm.01432 in the end while a Logic file can end with bip.0121. These names might mean stuff in the production phase but not for me while mixing so I strip that away. To exemplify a tack named "Audio Snare drum.bip0321" gets renamed to "DRM_SN". Notice that the name is in all caps to be more easily read.
Now to the more DAW specific part for you Reaper users out there. Keep reading if you're using another DAW though as this function is baked in to many DAW:s. In Pro Tools it's called batch rename but in Reaper there are several scripts doing the same thing. It's essentially a tool to rename many tracks simultaneously. In reaper i use a script called Script: amagalma_gianfini_ReaNamer (track-item-region renaming utility).lua and can be installed through the Reapack repository. I have mine assigned to shortcut N. With this script I can quickly implement the rules stated above to multiple tracks at the same time. I can strip the ends for shorter names, convert names to all caps and add prefixes for instrument groups. I can also use the replace function to replace long names like Snare to SN with the click of a button.
If you're in Reaper try it out yourself, it will make your projects look super clean in no time!