with sprite sheets, organization is very important.
it's best to keep the sprites in a grid, with the size a multiple of 8(8*8, 16*16, 24*24, 32*32...), and it would look a bit more nice if the sprites followed the same grid size.
organization can also eliminate the need for filler when done correctly, and lowers the image size.
For the most part, it's a 32*32 grid, and the bottom left in a 16*16
it's best to keep the sprites in a grid, with the size a multiple of 8(8*8, 16*16, 24*24, 32*32...), and it would look a bit more nice if the sprites followed the same grid size.
organization can also eliminate the need for filler when done correctly, and lowers the image size.
For the most part, it's a 32*32 grid, and the bottom left in a 16*16