I assume you've looked at these sites.
http://www.google.com/search?source=ig&hl=en&rlz=1G1GGLQ_ENUS333&q=henna%2Fmehndi+designs&aq=f&oq=
I don't know how else we can help you find what is "interesting" to you.
nice henna/mehndi designs....?
didn't find any interesting ones on google
2 answers
Maybe you should design your own.