How have you built a consistent identity transcending home servers and other systems?

With centralised systems, it's usually rather straightforward, i.e. I create avatar@twitter, avatar@github and it seems natural for the same person to own those two.

On decentralised systems such as #mastodon or #matrix the inference is not straightforward and in practice it's usually unrelated (i.e. @pete@qoto.org and @pete@ma.st refer to different people).

Could one link them where applicable?