You got that one right! Holding off using heart scrolls as much as possible gives you extra hearts (health) to work with. If you are going for a board clear (highest score), this insight is key.
It also helps a lot knowing as many mob patterns/mechanics. Only P2 and P3 mobs do not have a specific pattern to them, even P1 and P5, while not really having a pattern, are part of a "mob mechanic" - carefully observing the "death screen" reveals most of these patterns (some "activated" mob mechanics, need to be found out by actually using them, but most are easy to grasp when used a few times).