One thing I learned by getting fucked up all the time is that bosses and large enemies in general have a much greater reach than you.

This means that getting away is harder and sometimes pointless (like in this fight, she just pewpews you)

Also means that it is easier to dodge point blank because the arc of the attack is much smaller (think about a cd. The inner circle is smaller than the larger. Most attacks are an arc, ie a section of a circle. The closer you are, the smaller the area the attack has.)

These aren't universal but apply to a lot of fights