All article and section titles should use sentence casing (e.g. "A really long title" instead of "A Really Long Title").
Sentence casing helps distinguish common nouns from proper nouns--e.g. irradiated worlds (with Irradiated condition) vs. Irradiated worlds (the actual planet type).
Use the singular form rather than the plural form for article title names (e.g. Ship, not "Ships")
This makes linking to an article much easier in most cases, like using [[Ship]] instead of [[Ships|Ship]], and more freely allows the use of word-ending links like [[Ship]]s
However, if a proper noun is often referred using its plural form, like Credits or Pirates, then it can be fine to leave it as plural.
On the other hand, category names should generally be plural (e.g Category:Ships, not Category:Ship).
Use bolding and italicizing sparingly. Overusing bold or italic letters makes the article more difficult to read and obscures key information.
If in doubt, refer to Wikipedia's Manual of Style, or just use your best judgement and keep the pages you edit consistent relative to other similar pages.
Consistent formatting between pages of similar content will make it easier to mass edit the pages later using wiki bot accounts, if they are ever needed.
(Please feel free to discuss or make other suggestions on how pages should be styled or formatted, as the Style Guide is still WIP and would really benefit from an overall consensus.)
The following section contains user-submitted suggestions, these may be inaccurate or outdated.