It's an invented word. It doesn't really exist. It's derived from the phrase "to draw a blank," meaning "to fail to remember something."
"Can you remember who was president after James Madison?" "I'm sorry, I'm drawing a blank."
Your sentence sounds like the title of some kind of motivational essay. It seems to refer to three different ways of being ineffective. None of them are complimentary. You don't want to be any of them.
A "flip-flopper" means a person who flip-flops, changes his mind frequently
A "blank-drawer" is an invented word for someone who draws blanks--never has an answer for anything.
An "under-thinker" is another invented word. It means someone who under-thinks, doesn't spend enough time exploring all the possible things that could happen.