Is there a general template or format that other community creators use for the linking?

Honestly not really, everyone is kind of stumbling around trying to figure things out at the moment. You can autocomplete community names by starting with !nameofcommunity like this !ttrpgs@lemmy.blahaj.zone, but the problem there is that it takes you directly to the original instance (which newbies tend to interpret as it “logging them out”).

Best format I’ve found, which is not perfect, is to manually add the following after the autocompleted version ([Lemmy](/c/community@instance) / [Kbin](/m/community@instance))

So the above example now becomes !ttrpgs@lemmy.blahaj.zone (Lemmy / Kbin) which gives people on both Lemmy and Kbin a local link to go straight to where they can actually interact / subscribe.

I know better linking is something that’s being discussed and worked on by the devs but it’s one of many things we just have to be a bit patient with atm.