This is a great article about wet finishing your cloth, with easy to follow steps and pictures. As noted in the blog, wet finishing is the crucial finishing step in weaving and makes such a difference to the woven fabric.
Pretty much, I wet finish all my work, whether crochet, knit or weave. Stitch definition becomes clearer, the fabric relaxes and depending on the yarn you will get a different finish.
With natural yarns, you will need to sample and wet finish that, so that you can ‘change’ the fabric to what you want the finished article to feel and look like. Do you want it just to ‘full’ (where the yarn relaxes and expands) or do you want and almost felt-like finish.
Whatever you want your fabric to look like, a sample is a great way to see what your end product will look like.