I’m going to make some general statements in this post. Like everything, there are exceptions to every rule, but in my experience what I am talking about today pretty much holds true across the board.

“When you coach boys, you manage egos. When you coach girls, you manage emotions.”

Girls tend to be more analytical than boys. This means girls will not take generalities at face value. They will want to know why they should do something a particular way more than boys will.
Team unity is more important to girls than boys.
Girls may place more emphasis on ‘fair play’ than boys who are more likely to bend the rules.
Boys are more likely than girls to blame other people (the referee, the weather, the coach) if they lose. Girls have a tendency to blame themselves for a poor performance.
For girls, winning is not as important as making sure every player gets an equal amount of playing time.
Males appear to be more ‘self’ or ‘ego’ oriented and tend to be more ‘win at any cost’ in their approach to sport.

Boys need to be motivated more often than girls. Boys need to have ultimatums put in place that give them the motivation to excel at a higher level. In contrast, girls need to feel that you trust them, and will give them the opportunity to have input into the situation. To state it as simply as possible, boys need to respect you and fear you as a coach, while girls need to respect you and buy into your philosophy.

With older boys it is possible to “call out” a specific player in front of the group. The other boys will be motivated to not be called out themselves.

With girls this will often turn the team against you. It is much better to address them as a group, and them privately deal with individual players.

Like I said, these are not hard and fast rules, but have been generally true in my experience.