What do I do if I forgot how to make a "decent" smile on my face?
Force that smile on your face, no matter how negative a mood you are in. Try to think of happy thoughts and things that you find funny. Remember that it takes more muscles to frown than to smile :) Have a happy day!
Watch some puppies playing.
grin right big
Do you mean you first how to smile? Think of something in your past that was really funny, smile and paste that look on your face. Most people won't care if you are smiling or not.
the best looking smile is a natural one
Be comfortable when you smile. Start thinking about funny things, like everyone in their underwear.
do something that makes you happy and if no one likes your smile fudge them a least you're happy
Watch videos on www.youtube.com