Hi!
In the Apollo app (basically the reason i started using reddit and the reason i also left reddit lol) there was a very useful feature: friends.
It was not a mutual friendlist like facebook, and not even much of a follow like twitter; it was more a ‘‘favorite users’’ list.
Basically I added in there people that always commented stuff I was interested in and this helped me find new communities and interesting post without relying on other discovery ways. Seen the decentralized nature of lemmy, i think it could be even more useful than on reddit.
It could be nice.
In the meantime, since I use lemmy in a browser, bookmarks work OK for this purpose.