1) Public holidays, also self-created holidays should be written in upper case. E.g. I Love Free Software Day.
2) Choose carefully between "like" and "want." "Like" (as a verb, and there are other uses) means to be pleased by something or enjoy doing something, or to be attracted to a person. "Want" (in its most common meaning) means to desire something that one does not have. Sometimes the same thing is both liked and wanted. But often one verb or the other is the better choice. "Want" can also mean simply to lack something, without necessarily desiring it. (This is a less common usage.)
3) Oxford comma. Use the Oxford comma wherever possible. For example: a) Do not use it in the dedication "To my father, Barack Obama and Donald Trump." A comma after "Obama" would look as though I were claiming him as my parent. b) Do use it in the dedication "To my parents, Barack Obama, and Donald Trump." Without the comma after "Obama" it would look as though I were claiming "Obama" and "Trump" are my parents.
4) Be careful when copying and pasting text. When you copy text from one document to another, try to be sure that what is being inserted is consistent with what it is joining. There are many grammatical (such as tense and number) and stylistic ways in which the texts may clash. Be particularly careful when transplanting text of less than full sentences into a different document.
5) Try to assure that when a link is provided there are spaces around it between it and the surrounding punctuation, even if strict propriety would say that there should be no space there. If a reader copies the link, there is a danger that without the technically improper space the reader would copy the punctuation as part of the link.
British English vs. American English
1) British English to be used as general rule. The noun "licence" (verb and derivatives must be always "license") is to be used if inside a news item, but not when used related to a more "international" project (such as REUSE, where US spelling "license" should be used). When it appears as a part of the licence name (e.g. GNU General Public License) or inside the title of a conference/external page, it should be left untouched.