Custom editor -> Update when finish editing

I have been playing with [ExecuteInEditMode] and a custom editor, it all works well except for the fact that I have to hit "play" to force my editor to update my script. I have read the documentation but I haven´t been able to find a way to do this. How do I tell unity that it has to update the values when I finished editing in a custom editor?

To be more specific, I use all values at the Start() method, so I am guessing the values are changed but Unity needs to recompile. Is there a way to avoid this? Which is the usual way to handle this?