Ive done it before all you can do really is take quite a big bag because the only things you can get for the bikes are that one posted by rhaines and like a tool pouch which sits on the back mudguard, they are made to be light so they are not going to make anything massive to go on the side of them to carry things , you may as well get a trail bike if your doing that ?
Or get one with a side car and put all your stuff in their