Appearing before the Board. All Board meeting agendas provide for Open Discussion. This is your opportunity to speak to the Board directly. Just sign in, and take your turn. Your time may be limited, depending on the number of people who wish to speak.
Effectiveness there is no different from any other public speaking.
Offering feasible alternatives may be more effective than mere opposition to a proposal. But it s your call. In an effort to increase the opportunity for direct public input to the Board, it holds one meeting each month in a local school building. Anyone can appear at that time, not just families involved with that school. Your imagination and political experience are the only limits to the other techniques available to you.