Another useful Tip if you are trying to get good crowns on monsters is to use tools that show Things like Monster HP and Size.
I am using the tool "Smart Hunter""Smart Hunter" and it shows me if an monster has a crows, it'sthe monsters Hit-points and the Hp of it's body parts as well as other useful things like player damage on an monster.
Smart Hunter does also show the size of an monster indicated with the according crown symbol under it's name, which could be small silver/gold crown or large silver/gold crown.
As far as I know those helping Tools are not forbidden to use, since they do not alter your account and I havedid never gottenhear any negative feedback about themSmart Hunter so far.
What I do when I am looking for a specific crown is: I enter a quest, regardless if it's an investigation or one of those event quests and look if the monster in it has any gold crown size. This saves me a lot of time, since I can easily sort out quest with monsters that don't have the right size. (since doing the same investigation twice gives you a monster with the same size)