The general sign for "little" as in "small" uses "flat" hands to show the
size.
LITTLE / small:
Little as in "a very small amount."
Little as in "tiny."
Little as in "a little bit."
Sample sentence: Is your bedroom a little bit dirty?
Note:
Actually, in that sentence (above) you don't really need
a separate sign for "little-bit" because
the concept of "little bit" could be incorporated into the sign "dirty"
by reducing the intensity of the sign "dirty."
Note: If you mean "little" as in
"little boy," you should use the sign "short-height."