1. Say more positive things to your child each day than negative ones.
It's easy to get caught up in criticism and correction, but if all your kid hears about is what he's doing wrong, he might begin to believe he can never do anything right. Give as much emotion, energy and attention to the good or just not-bad things your child does as to the bad ones. If necessary, set up situations specifically to give yourself an excuse to praise your child. Frequent smiles and hugs can go a long way, too.
2. Find something your child loves to do.You're always going to have to spend a certain amount of time pushing him or her to do things that are hard and frustrating and discouraging, but everyone needs to spend some time doing things that are fun and fulfilling and empowering, too. If your child has a hobby or a special interest, encourage that (without taking over entirely). Even if all they like to do is listen to music or watch TV, you can discuss their likes and dislikes and give kids a chance to "show off" their knowledge.
3. Give your child responsibilities.
This can be hard to do for children with special needs, who may not be able to follow through on normal chores. But with a little imagination, you can find small but important jobs from which your child can get a sense of contributing to the family without risking failure or blame. It can be as simple as putting a clean trash bag in an empty can, bringing the newspaper inside, making sure lights are turned off, or sorting recyclables. Having a "job" of any sort is a self-esteem booster.