It also depends on where you are. In some wealthy areas, if you charge
$10 per average design, it might be viewed as too cheap, and you won't
get customers. In other areas, charging $10 per design might seem too
expensive. You just have to feel your market.
Here's my way of pricing but again, it's only my way and i've met so
many different henna artists price their work differently:
small designs $5-10 this includes little butterflies, other small
animals, some abstract work
medium designs $12-20 this includes small mandalas, wrist bands, and
half a hand henna
bracelets, armbands, anklets, lower backs $20-30
hands henna $25 per hand, including all fingers, both sides $40 each
large designs $40+ full back, full leg, head henna and wedding henna.
Henna art is priced differently depending on how intricate the design
is & where it is applied.
I hope this helps you determine your own price chart.
Good luck!