If your parents smoke around you, your clothing and other items may smell like smoke. Smokers don't mind the odor because their noses are no longer sensitive to it. So your parents don't notice the smell, but you probably do.
Talk to your parents about the problem to see if they can help pose some solutions. Ask them if they could start smoking outside. If they are not agreeable, understand that smoking is an addiction.
Keep your dresser drawers, your bedroom door and your closet door closed. Let your parents know that you are keeping the door closed to maintain a smoke-free zone in your bedroom. If they do not want the door closed, ask if you can put a fan in your doorway blowing out.
Post a "No Smoking" sign on the door to your bedroom and ask your parents to respect it.
Put scented dryer fabric sheets in your clothing drawers. Layer the sheets between your clothes. Tuck some dryer sheets inside the clothes in your closet.
Cover and clothing that is hanging in the closet and that doesn't get worn often with a large plastic bag. Turn the bag upside down and cut a small hole in the center of the bottom. Put the hanger through the hole and pull the plastic bag over the clothes.
Spray your clothes with a fabric freshener, such as Febreze, the night before you are going to wear them. You could also spray a little bit of your favorite perfume or cologne on them. Perfume or cologne doesn't remove the smell, but they may mask it.