You could go to the life stories and blogs section here to see the different ways people became poly, or open, or whatever, and how they practice it now. It's usually a long hard road for many people at first, and you'll see the variety of ways people have handled it in their blogs.
It varies a lot, depending on people's ages, whether they are in a couple or not, whether both partners are poly, or one is mono, whether they are straight, gay, bi or pansexual, whether there are kids in the mix, whether they are Christian, pagan or atheist, whether they are fully open or poly-fideltitous, whether they are seeing their partners regularly or are in long distance relationships, whether there has been cheating at first, or a careful thoughtful progression. Ad infinitum.
Love withers under constraint; its very essence is liberty. It is compatible neither with envy, jealousy or fear. It is there most pure, perfect and unlimited when its votaries live in confidence, equality and unreserve. -- Shelley
Mags, F, 60, poly-dating, loving and living with
miss pixi, F, 38
Punk, 41, M (dating since Oct 2015)
and a few more casual relationships