One of PokéCommunity's greatest assets is the CSS support, with only AO3 getting anywhere close, and it can help with stories a lot. That said I don't actually do that much formatting - I use a premade PokéCommunity CSS template to style most of my recent material, which sets up ready to use:
* A specific typeface for non-story sections (author's notes, etc) with as little additions as possible respect to the viewer's theme/style
* A specific Book-type typeface for story sections with indentation and letter spacing to make reading long sections easier
* Regular styling and spacing for headings , with each also given a HTML anchor or equivalent
* font-variant effects to denote various in-universe situations such as loud speakers (Dialga in Beyond Today), loudspeakers or PSA, condensed or shadowed text for telepathy, and change of indentation or alignment to indicate the distance or direction an offscreen voice comes from
Colour and size is not really something I make much use of, because it can get in the way of getting your work in a print-ready format, for epubs and the like, but some light usage should be no problem.