To work out how I want the gags for my cartoon to work, I've made little storyboard/gag drawings or thumbnail sketches. These are small, rough and quick sketches. Essentially these are ideas on paper. In a studio production these would ordinarily get cleaned up and submitted as a storyboard, but since I'm doing this myself, I'm not going to need clean boards.
Thumbnails are quick and easy to draw and, if it turns out that they don't serve the main idea, they are easily discarded.
Animators also use thumbnails to plan out the poses for their animation.
In the thumbnails for my cartoon the baby is lowered into his highchair, a spoonful of food is offered from the left, he twists away from it. More food is offered from the right, which he also declines. Both spoons enter, he grabs them, propelling the food back at the offscreen servers. A bowl of gloppy food is deposited on the tray. He raises his fists high and slams them down on to the tray sending the bowl and it's contents flying up out of frame. The bowl lands quickly, then is filled with the gloppy food. The baby laughs and does it again. He laughs again and tries it a third time and accidentally hits the bowl, splatting the food onto his face. A spoon enters and scrapes the food from his face and feeds it to the now cooperative baby.
This is just one page of thumbnails I've made for this little film. Time will tell how many pages of sketches I will need before the short is finished.