What kind of groups are you talking about?
Most people just need to look around at what they're doing, at whatever is a natural community for them, whether it's a group of friends that they do things regularly with, or work – work is one of the most common communities where people are interacting in an important way with other people. Then there are faith communities of all kinds, recreational groups, 12-step groups. I think it can be almost any situation.
The key is trying new ways of being more open or speaking up so you don't feel like if you get near anybody that they're going to roll right over you.
Let's say, people who distance with sarcasm in their couple relationships. They may think about it and realize that they do it with people at work, too. So, they might practice sitting through something at the office and noticing what they're about to say, and instead, choose to act in a different way. They might do something really unusual for them, like leave somebody a note saying "You did a great job on this" without saying anything sarcastic.
It could be anything that represents how they want to change, even just being more open about feelings.
It might seem counterintuitive to people to start with a group to solve a problem at home.
When people try these new behaviors with the beloved and it doesn't work out well, they give up—the more times you fail at something, the more you just kind of begin to wilt inside. That's very true of people who feel discouraged about relationships. So, it starts with trying it in the community and then taking it back into a new attempt at being intimate.
That way, if it's awkward and doesn't go well at first, then they're not as crushed.
And finally, this approach of trying out new ways of being more steady; if it's someone who's being approach-avoidant, saying, OK, this time, instead of starting something and running away, I'm going to get more involved in this community and stay, even when I want to run, and I'll find out how that feels, and take that into a couple relationship.