Materials:

• 1 - 50g ball of Black 4 ply knitting worsted
• 2 - 50g ball of White 4 ply knitting worsted

Designer’s Note:
SIZE is for a foot length of 9 to 10 inches.
I don’t have time right now to do patterns for different sizes, so I would suggest for larger sneakers, use a larger hook size. I wouldn’t go any larger than a size 6.00 mm (J-10 US).
For smaller slippers, use a smaller hook. I wouldn’t go any smaller than 3.75 (F-5 US) as it may be too difficult to work with. You could try a sportweight yarn with a smaller hook for even smaller sizes.
Update: - I made a pair with a 4.00mm hook and they fit a foot length of 8 inches.