as a GM
I try to run it where the players have the choices to go one way or another and I'll adapt as best as I can on occasions I will round the players back up and push them in the general direction of where I want you to go either by creating a plot to event that will temporarily force you in the direction or drop enough hints or clues that you'll eventually go in that direction.
I also do not follow module strictly by the book I like to have handful custom rules change up things from time the time to keep players on there toes's I may even throw in a couple of impossible situations that are not possible at your current level you can blame this on many years of playing too many adventure-based RPG video games such as fable where there's constantly things you have to do that are directly tied to the story or indirectly but all have an impact one way or another there are side events that can only be done at specific levels or if specific thing to been done
If things get too complicated I will either try to cut out what is causing the problems although I'm not big on giving people something and then finding out that it was little more broke that I thought it was and then taking it away just because it's broke usually all tried balance it if this is not possible then I will find a way to take it away without seeming like im a dick and I try my best not to kill PCs off although I can't really help it when it misfortune just happens to players