It is really easy.
1)Make your Jamaican flag
2)Pull the string at the bottom of the Jamaican flag with you mouth :wink:

Hmm…I’d rather not put my string in my mouth for fear that others might use it. I think this method would prove easier:

Or even this:

Or you could do a Rolling Star. I know its an off string trick, but can do it on the string by throwing a Trapeze and putting your thumb in the loop and pulling it open. From there, perform it as you would off string.