What are the rules of making a bouquet for the table? There are no rules! There is only heart and passion. Go out to your yard and pick anything interesting or having color. I picked Hosta blooms, tree hydrangea, Day lilies and a stew pot of flowers.
Worth mentioning, when you pick Day lilies, make sure you have a few buds on each stem as Daylilies send out a new flower each day that blooms in the morning and closes at night. A new blossom will awaken each new day.
On the subject of vases, anything that will hold water can be a vase. I used my milk pitcher for this bouquet. I rarely drink milk anyways.