A bad report card isn't the end of the world, but it is a fairly big deal because it means your child isn't living up to his full potential. Aside from having a long conversation with your child about trying his best, a few creative punishments might be just what it takes to encourage him to do better next time around.
Supervised Homework Time
You probably want to trust your child to complete his homework to the best of his ability, but many children pull a fast one and say they've done their homework when they really haven't. Not completing homework causes a decrease in your child's grade, but it can also leave him unprepared to be successful on tests and other projects. If a bad report card has come home, become extra vigilant. Stand over your child and watch him do his homework. Go over the assignments thoroughly to find any mistakes, poor handwriting or incomplete sections. Continue watching your child as he fixes his mistakes. Most children don't appreciate mom or dad hovering and might be willing to take the initiative to improve his grades if he's under constant supervision.
Stop by School Unannounced
Nothing is more mortifying for a child, especially a middle- or high-school aged child, than mom or dad showing up to see what is happening in the classroom. Arrange the visit with the administrators at your child's school and with his teacher, but don't tell him that you're coming. After school, tell your child that you came by to see what he is learning so that you can help him pull his grades up. Promise to come by once a week or so until his grades are acceptable again. The threat of embarrassment might be just the motivator he needs to become organized.
Chores for Grades
Assign a chore value to each grade, so an A equals zero chores and a D or F equals two or three chores, and so on. When the report card comes home, your child has to pay you for the grades accordingly. Think of unpleasant chores, such as washing all the windows in the house or scrubbing the inside of the refrigerator, to make the consequence more effective. While you don't want to make your child feel like a failure, getting low grades most likely means that he's not doing his best work. An influx of chores might encourage him to try a little harder and get those grades up by the next report card. Extend the consequence to homework and other assignments to drive your point home.
Though not a punishment, challenge your child to bring his grades up. Promise a reward for each grade that he improves on. Choosing a restaurant to visit for dinner or getting to pick a Saturday afternoon family outing are appropriate incentives for working harder. Make your child do more school work if he's getting poor grades as another potential motivator. Purchase a workbook from a teacher store or download worksheets from the Internet. Require your child to complete this extra work for any subject he's getting bad grades in. The additional work, as well as the loss of time to do more enjoyable things, might motivate him to try harder next time around.