The sign for compliment is a modified version of the sign for SCHOOL and/or CLAP. The difference between the two signs is that the sign for compliment is done a bit softer and the contact is more from the finger area of the dominant hand to the palm area of the non-dominant hand, (not so much palm to palm contact as in the general sign for SCHOOL).
Also the sign COMPLIMENT is sometimes held a bit more out from the body -- especially if you are complimenting someone directly (done slightly in the direction of the person receiving the compliment).
COMPLIMENT:
Also, you could express the concept of "compliment" via other methods such as informing someone that someone else had said something POSITIVE about them or NICE about them.
See: SCHOOL
Notes: