CBs suck. I address them preemptively for the most part by mining info.
1. Acknowledge the CB and others as human beings, show courtesy, warmth, engage them. In most cases, the reason you are being CBed is that someone who knows the girl you are talking to can see your obvious, single-minded intent on bagging their friend. Remember that scene in Godfather where the restaurant guy goes ballistic over comments about his daughter, and then Michael C smooths it over? That's what you are aiming for (unless AMOG or "Rudefat," different rules there, watch PUA videos on youtube for that). Befriend the CB, social proof, then ignore them all and move off to do something else for a few. Slow play, withdraw, especially if there's another good looking woman you know or can strike up with, and you will often find the CBs feeling bad for interrupting you, coming back around and trying to "sell you"on the girl. I have had CBs come up and bring me the girl's phone number later.
2. Another CB is the "we are leaving now, or we are going next place." To handle this, you have to mine some basic info out of all targets IN ADVANCE, preemptively, before the CB pops up, "hey, what's the occasion?" then "what's going on tonight?" "Just out, heading over to X in a bit." "Oh cool, I'm headed over there later to meet people (even if alone, you can be headed anywhere to meet people at any time, I "meet people" wherever I go), they have great Y don't they?" Then immediately change the topic, and continue your patter. If nextplace is a party or somewhere you'd like to go anyway, and the girl is there with people, break and try to meet the friends right then and there if they look cool, work an invite to the party or nextplace. This works very well on bachelorette parties and GNO. Once they like you, you can slowplay more. "It's getting late, lots to do tomorrow," "NO, STAY!" You have won. And along these lines, never buy any of them anything unless it's your turn to buy the round. You aren't ever winning if you are buying them drinks.
3. Probably the best way to avoid CB is not to be "that guy," the cruiser for drunk chicks, so obvious. Be the "befriender of all," man o plenty, and involve the target in your befriending. Be captain social, pick the most obvious AFC you can find and work him into the conversation with target. Build your sets. I almost never get CBed any more because as far as the potential CBs know, I'm this "new great social guy introducing everyone around" they met, the man o plenty, not an obvious pressure artist threat to their friend.
4. If your own "friends" are CBing you, dump em as friends, get new ones. Life is too short to spend one extra moment with selfish or unaware people.
Just some things that work for me, YMMV.