From mid-July to mid-August, Mont Dol (near Dol-de-Bretagne) organise an evening market on Wednesday evening from 5 to 8pm.
You will find art and craft as well as local produces.
It gives you a chance to buy straight from artists and producers.
Whilst there, you can go and visit the Moulin (wind mill) and enjoy the view of the bay from Cancale to Normandy. You should see the Mont St Michel on a clear day!
Dol-de-Bretagne is worth a visit too! See my other posts about Dol.