Does this sign work for all types of balls?
This is the general sign for the word 'ball'. However, if you are talking about specific sports like basketball, baseball, or football, ASL uses completely different signs that mimic how the ball is handled or thrown in those specific games.
Should my fingers touch when making the shape?
Your fingertips and thumbs do not need to press tightly together. You simply bring your hands close enough so that your thumbs almost touch, creating a clear, round outline of a ball in the space between your palms.
How big should I make the ball shape?
Keep it a natural, medium size, roughly the size of a softball or a grapefruit. Your hands should be comfortably placed in front of your chest with your fingers arched, without stretching your arms too wide.