Over the years, the hilariously inept depiction of breasts in comic books has actually given rise to many helpful guides on how to properly draw the main reason many young males get into comics in the first place. They all boil down to one thing: Stop treating breasts like unmovable, quantum events that the rest of the universe revolves around. For example, when a character turns, her chest shouldn't stay right where it was -- as if trying to make sure that no one sneaks up on them.
Dynamite Entertainment, DC Comics
You might say they are keeping the heroes abreast of the situation ... we'll let ourselves out.
Failing that, it would probably be a good idea to remember that breasts are meant to be three-dimensional objects and thus shouldn't be drawn as two modesty flaps occasionally obscuring a character's midriff.
"Hey, a girl has to have some self-respect."
And while we sorely wish it wasn't the case, thousands of years of advances in the field of human clothing have sort of proved that breasts can only really be held in place with bras, not bitchin' leather belts. If you feel like that's too many rules for you to remember, you can always print out this page from Jade Warriors and look at it whenever you want to remind yourself how natural-looking breasts should never, ever be drawn.
Origin story: woke up naked in a belt store.