The trick comes to when you have to pass through a vision cone, in which case you will have to pass stealth checks every so often. Which, especially at early levels, can be hard to pass consistently.
Well this is my issue currently. being on a first run of the game I don't know where are the nemies when I pass by to avoide those cone of vision. I kinda envisonied stealth scouting as a way to learn what is ahead. But so far, It just get me cut alone most of the time.
I guess that I will use more invis scrolls ty.