As an entirely self-taught author, living secluded in my room most of the time, I've still managed to make up a few rules of my own when it comes to writing. I'll share them with you.
1. Sentence Length
Keeping your sentences' length to a good "level" is one of the first tips you should earn when you write, no matter the purpose (school, law, job applications, blogging, etc.). It is not so much excessive length or extreme briefness that can go wrong, as it is inappropriate length.
A series of short sentences do not necessarily make action seem faster. It rather makes it appear broken into pieces, "chopped up", which, while it can be your wish, is not always a desirable effect.
Longer sentences with carefully chosen words can create beautiful descriptions of landscapes. "Chopped up" sentences, as I mentioned above, can create the ambiance of a confused, near-death person whose thoughts wander around a room. Let's try describing a landscape with such sentences.