I have a small ubuntu server running on a rockpi 4, I use it for everyday services like rss feeds (miniflux) and media (jellyfin). The only way I have found so far to be more resource efficient is to download movies and shows at lower resolution, this can reduce used bandwidth to a tenth. What other ways are there to save power and bandwitdth for everyday tasks?
For power, using a wired network instead of WiFi is going to help.