Any good resources for GM tactics?

As a GM I'd like to feel like I fully understand how to utilize my monsters tactically, but over the past couple months as I've been running the beginner box and now leading into Abomination Vaults, I feel as though I'm very often just making three strikes with an enemy or moving and striking twice unless the enemy has a very specific action in its statblock which is obviously better. Like a dragon is obviously supposed to use its breath weapon, but then I ran goblin warriors last night and I couldn't even figure out how to use their scurry reaction beneficially.