In general I tend to have a sentence at the end of my paragraphs that will lead to a different point. It's not so much that I directly say "To explain this I need to talk about XYZ", but more like mentioning "XYZ" and then starting the next paragraph that explains that "XYZ is a technique to do <stuff>" or something along those lines, depending on the context.

Context, and more precisely having a common thread throughout your writing, is always the most important thing. How exactly you are using this is up to you and depends on your task and goal. It doesn't really matter whether it's an e…