How do I healslut In FFXIV?

Just to be clear, I know how to play healers pretty well in FFXIV, but I've never healslutted before and I don't know how it would be different from normal healing?

I know there's a "0 dps" healslut play style, but since healers are expected to dps in FFXIV I assume that would be a thing people only do if everyone consents, if I'm healslutting with a tank duo or solo queue how would healslutting differ from just playing a healer the intended way?