Banneton or bowl?
A banneton should be well coated in rye flour on the inside. This is achieved by dampening the basket with a water spray, tipping in a small amount of flour and smoothing it all around the basket so that it sticks. Leave to dry and repeat the process over a few days. Once your banneton is conditioned in this way, do not wash it.
If you are using a bowl during the proofing stage, give the inside a very light coating of oil. Tip in a small amount of rye flour and rotate the bowl around until the inside is completely coated in flour. Instead you of oil and flour you could use a linen tea towel. Rub flour into the surface of the tea towel and use it to line the bowl. Do not use a cotton tea towel - only linen.