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.
I guess it depends on your definition of “self hosting” but I’m in the process of migrating a lot of my services to a remote vps on vultr. It doesn’t make much sense to have a big, hot server running at home that needs capacity to cope with peaks but isn’t used 99% of the time.
Sharing server resources with other virtual servers is the most significant least pain to benefit ratio action I can think of.
All that will really be left at home is a torrent client and gerbera (upnp) instance which can happily run on a NUC with an nvme. gerbera won’t do any transcoding so the load is negligible.