Insert a wooden skewer into the bottom of the pumpkin. 

Place the skewer into a piece of styrofoam to allow it to dry.

Grab your inks and a small spray bottle of rubbing alcohol.

Use one or more colors and place a few drops on the top of the pumpkin.

Turn and twirl the skewer to get the ink to move.  

Hit it with some rubbing alcohol and watch the colors blend together.

Let dry overnight. 

Use a poly spray to protect them