+ DO NOT USE ALL UPPER CASE. Some would call this "shouting". It is not as easy to read as regular "sentence case".
+ do not use all lower case. Again, sentence case is easier to read.
+ Use paragraphs to consolidate your train of thought. One really long paragraph is hard to digest. Same with not using paragraphs at all (just individual sentences with blank lines in between). When you are moving onto a different thought, make a new paragraph. Group the sentences into paragraphs is actually easier for people to digest what you are trying to get across and it is easier for them to see when you are on to the next thought.
+ Photos or drawings can help illustrate a point and can often better convey the point better than just describing it.