Never use both a tab space (first-line indent) and an extra line space to separate paragraphs. One of Microsoft Word’s worst defaults (and only on Windows) is the added after-paragraph space, which leads to bad formatting as most writers prefer the tab key to signify a new paragraph. Delete the after-paragraph spacing unless you wish to signify a new paragraph with an extra line space; all articles on this website demonstrate the extra line space.
Do not use the space bar for first-line indentations or the return key for extra line spacing. This is bad form.