People, processes and tools

"People" problems can be minimized by careful interviewing. Talking to the person, letting him chat with the team, and possibly solve a small problem with them can give you some insights.

Having a rigid process is often an overkill for small companies. You hire people that can communicate, and they keep going together because of that. But if you enforce some process on them, it might be harmful and decrease their desire to cooperate. I've seen that.