If you are looking for ideas you should search around the forums. The “hey what’s a good idea for automation” topic probably has a hundred different threads. I would recommend just reading the forums regularly, I get all kinds of great ideas just from reading what someone did (i.e., I recently built a fireplace log monitoring system using ESPHome based on some ideas brought up here, it was a fun project that my wife thinks was positively silly to do but it took me 20 minutes, $5 of components and adds a huge layer of nerdiness to my home automation).
You can also look at topics already deep into responses like: