Any Advice/Information that nobody might not know about?

I got my third-hand (or maybe even more) Steam Deck like +2 months ago, is there any advice/information that I should know, do, or do not do for the Steam Deck?

I've watched some videos on YT; stuff like "Things you should know about", "You should do", etc but I feel like they are more stuff that I should know/do/do not do

E.g., Just now I saw someone said that Decky sometimes would cause an issue with some game/stuff, and I don't think I saw someone said or even mentioned that on YT videos that I've watched.

So I would like to know other advice and information for me; a new user, for others that might not also know about it, and for future users that might have this kind of question too