The sign for "different" is based on the sign for "but." The sign
"but" generally uses a "smaller" movement, however, it may be done quite
large depending on how excited the signer is. It is also very common
to fingerspell B-U-T when you mean "however."
BUT


Animations:
but
different
very different
different: other version
DIFFERENT:

The sign for "but" is (in general) the same as the sign for
"different." However, I suggest that the sign for
"different" uses a larger motion (in general) than the sign for
"but."
but or
"DIFFERENT"


Suppose you are excited though and want to make a point that two things are
different, in English you would say BUT! and then go on to point out the two
things are different. That same principle applies in ASL.
Here I'm showing the same approach using the sign "BUT!"
BUT!




You can do the sign larger to incorporate the concept of "very."
As in "Those two things are very different!"
very-DIFFERENT:


It is very common to see the DIFFERENT" sign used to mean "various" or
"several different" versions of a thing. This is accomplished by
signing the sign DIFFERENT two or three times. Start a bit to one side and
move to the other side as you sign DIFFERENT.
"A variety of different items" = DIFFERENT DIFFERENT




My facial expression in the above sign is saying, "yah, it's true, those
really are several different kinds..."
Also see:
BUT
Also see: SAME