Decky Loader gives you some really cool add ons that can help enhance your experience. Lots of different addons are available, but Powertools is popular and can help tweak things to help stretch battery usage a bit, and since I use Emudeck and other non-Steam apps (like the Heroic launcher and the Epic Game Store launcher), SteamGridDB gives images to those otherwise iconless apps.

The right touchpad as a mouse is so intuitive and useful in general, things like the ROG Ally seem less capable (even if they are much more powerful and have better specs than the Steamdeck otherwise).

If you’re a little less CLI savvy, KDE Connect will be much easier. Winpinator on your desktop and Warpinator on the Steamdeck works well and can sometimes help if file copies via KDE Connect fail.