Anchors are arguably the most important part of a hypnotherapy session. As the session unfurls, I take notes on anything positive you've said. Sometimes I'll ask you to rephrase something, so that it becomes a positive, as I never want to anchor a negative. Your subconscious is the oldest part of your mind, and functions much like a small child. If you tell a small child "you're not in trouble", they often skip over the "not" and hear "you're in trouble". But if you tell them "you are safe, you are loved, you are good, and let's find a way to fix this", that's what they hear.
For instance, if your adult self says to your child self "you are never mean, and I could never hate you", I might ask "so if they are never mean, what are they? If you couldn't ever hate them, what could you do?" So the client might respond with "you try so hard to be kind even when you don't feel like it, and I love you". Or they might say "you always try your best, and I admire you so much".
Note that these are each so different! I will use your words to anchor, because it is very important that the words are true for you. Often nearing the end a session I will have a whole list of anchors to repeat back to you before bringing you out of trance. Sometimes I will ask you if you want a physical reminder, or signal, of this anchor. Some people give themselves a thumbs up, or brush their hair out of their face, or put their hand on their stomach or chest. If you chose to have a physical reminder of the anchor I will ask you to do that physical reminder as I repeat the anchors to you, giving the suggestion that every time you do this physical reminder, you will be sending the message to every part of you all the things that anchored in this session.
Physical anchors are extra powerful in my opinion and experience, because clients can use the physical reminder whenever they feel like they need it. I've used my own while in difficult conversations, before big events, and while awaiting medical results I was nervous about. It is subtle enough to use any time, any place, and instantly calms my whole system. Clients have reported similar experiences using their own signals in situations that previously would have been emotionally tumultuous for them, becoming manageable and even easy because they have access to this new tool now.