I think many people agree that AOOs are an important balancing factor in using attacks like disarms and trips. However, at the same time, they often make those attacks very rare unless you have the appropriate improved X feat. I think this house rule creates a balance.
House Rule: If you attempt a disarm, trip, or sunder attempt against a creature with a Base attack bonus of 5 or more less than your own, you do not provoke an AOO for the attempt.
House Rule: If you attempt a disarm, trip, or sunder attempt against a creature with a Base attack bonus of 5 or more less than your own, you do not provoke an AOO for the attempt.