I typically allow about 3/4 " ease to a person's wrist measurements when making bracelets.

But bangles are different. They have to be just large enough to go over the hand but not much bigger or else the bangle will be too loose to wear.

You could use a tape measure but Australians, Janine and Lionel Zschech have an easy alternative which doesn't require one.

Their tutorial (update : link no longer works) will also work for wire artisans who make wire wrapped or woven cuffs.  They use a card strip and some tape. The paper template should just fit around a hand at the widest point - the knuckles. This nifty trick also gives some indication of what the cuff will look like for any given width.

Another advantage is the ability to get the measurement for anyone who is far away. That is exactly why they wrote the tutorial.  They make beautiful wooden jewelry for their Etsy store Wood 'n' Piece.

Much of the wood comes from "recycled timbers from our family farm located near the Barossa Valley" in South Australia.  Their foray into artisanal jewelry began when Lionel made some durable play jewelry for their daughters. They were taken completely by surprise when Lionel's co-workers started placing orders after seeing his efforts. As they say, the rest is history.

Shown here are some of my favorites from their store :

Jarrah Hearts Organic Wave Bangle
Jarrah and Norfolk Pine Layered Wave Bangle
Jarrah Wood Classic Key Necklace
Blue Foil Bead and Wood Bangle

Before You Go :
Original Post by THE BEADING GEM
Jewelry Making Tips - Jewelry Business Tips