It's an opportunity to discuss with your barrister how they will put forward you case based what you'd like to achieve and any evidence you have for why the court should support that - essentially it is forming the 'game plan'.
It'll make their job much easier if you can give them clear position of what you'd like.
Raise anything which you think will reinforce your argument. It's also worth discussing anything which you think might be brought up against you so that your barrister has a response ready in case it gets brought up - rather than being on the back foot.
I've dealt with a couple of barristers and I've always been impressed by how they can prepare and understand your situation.