The most effective way to advocate for your child at IEP meetings is to be prepared. You must walk into the meeting knowing what you want to achieve. When I go to an IEP meeting, I take a couple of things with me: (1) binders that hold all of my son's IEPs since kindergarten: (2) a tape recorder to record the meeting; and (3) pen and paper to take notes.
I'm told that most parents come to the meetings with nothing--just empty-handed. The more prepared you are, the more prepared the school must be. So, the first thing you need to do is get some 3-ring binders and gather up all of the paperwork you can find, every IEP, meeting notice, behavior plan, etc. Put them in order by date. Put divider tabs between the years. Get some pocket folders with 3-ring punches in them and put standardized tests in one pocket and grade cards in another. It's very intimidating to walk into a meeting with a stack of binders labeled "Your child's name; IEP; Vol. III).
Take notes at the meeting. Write down the date and time and the name of every person in the room. When you walk in, put your tape recorder in the middle of the table and turn it ON!! Yes, you absolutely have the right to make a tape recording of the meeting. There must be a representative of special education present.
Before the meeting, know what you want to accomplish. Does your child need less homework, reduced pencil and paper assignments, a classroom aide, speech therapy, OT. Know what you want and then ask for it. Be prepared to explain why the thing you want is necessary and how it will help your child succeed. If you have homework examples, test scores, reports from your doctor or therapist, take them to the IEP meeting.
Most importantly, do all of this in a spirit of cooperation. It is easy to go to these meetings and feel angry. However, if you act angry, then nothing is going to be accomplished. Remind yourself and those around the table that your child's success at school is the thing that matters the most. It is much harder for the school to say "no" when you are being polite and professional and stating your case with facts. Trust me, the school officials find it somewhat intimidating to have a prepared parent walk into the meeting. It drastically changes the school official's perception of what they can get away with telling you if they realize you are prepared. If you are angry and blame the school for everything that has happened with your child, you are going to be told "no" to everything. Please don't be in denial about your child. As his or her advocate, the best thing you can do to help your child is be honest with yourself about your child's limitations. This doesn't mean to settle for anything or nothing. Be able to explain why the relief or action you are seeking from the school will benefit your child and the school at the same time.
I've also found that walking in with a box of donuts and some coffee can get a meeting off to a really sweet start.