Be available when your child is doing homework, so that you can answer a question if there is confusion. If possible, it is better for you to be in another room, so you are easily accessible and yet not a distraction. Look over the homework when it is completed. Do not correct it unless you have checked with the teacher. Seeing the pattern of errors is often helpful to a teacher.
Study groups are often a good strategy.
Your child may benefit from studying with one or two classmates. However, make sure they are using the time to study.