Will this link explain things better? "Create/Edit a Madlib" 
There does seem to be an issue when you try editing a madlib. It seems to duplicate your original blanks. Just might be a glitch. So if that happens, you can create a whole new madlib. Remember to always test before making it public.

An example of a short madlib I created can be seen below:

{blank:noun#1} woke up to a {blank:adjective#1} new day.
She felt absolutely nothing could go {blank:adjective#2}.
She dressed in her finest {blank:noun#2} and shiny {blank:adjective#3} shoes.
She hopped down the stairs to meet {blank:noun#3} , her {blank:noun#4} .
Together, they would have the {blank:adjective#4} day ever!

The blurb above goes in the 'your writing goes here' section.

When you scroll down to 'Madlib Blank Types', then you can type in the noun#1, adjective#1 etc. etc. Either way, the link I provided should explain things a bit clearer if you get confused.