What to do, what to choose.Follow

A monk can do various crafts that benefit, so it's hard deciding on one :s

Since a monk wears leather armour, Tailor would be good and they can make fist wraps too.

But Woodworker is good too if you like to use cudgels and staves.

And Alchemist for the monks combat arts.

Jeweler is handy for jewelry and belts.

Carpenter is good for boxes, sales crates.

Provisioner so you can make your own food and drink

Just choose out of them what you like the best.

My main is a Warden and I chose to be a Tailor. And made alts to craft other things.

If my main was a Monk I'd choose Tailor still, only 'cause I like that best.