I can't stress this enough when I see a bad tutorial: Make it quick and to the point.
For example, If you are making an after effects tutorial on how to make a logo, do NOT start with "Hello everyone.... I'm John Smith... This is my channel... Please consider subscribing and leaving a like in the video section below.... It get so tedious because most people usually watch tutorials on the run. They don't want that they'll probably fast forward anyway.
Also... Also, also, ALSO, stay relevant. Don't go over the the after effects layout because if they're looking to make a logo, odds are they already know what it looks like.
Also, speak fluently and don't say "ummmmm" and "uhhh" or my person favorite: "....yeah"
I hope this helps. I'm not a professional tutorial maker but I've seen a lot of them and these are just what I look for in one.

Good Luck!