How to Make Someone Smile

1. Smile at them. Don't have a forced smile, but a soft caring smile. You can even practice in the mirror.
2. Tell them a funny joke. Inside jokes work really well, especially if it is something only between the two of you.
3. Find something funny online and send it around in an email, such as funny cat clips.
4. Compliment them sincerely. Tell them how you love their shirt or how their hair looks.
5. Invite them to do something fun with you that you will both enjoy. Go bowling, swimming, or something else fun and active.
6. Pick a dandelion or blade of grass and give it to them. Say things such as, “I got this especially for you!” or "I picked this weed just for you!" It is different and might make them laugh at your silliness, make them smile at your sweet nature.
7. Listen to them. Try to understand their thoughts and be in their shoes. This shows you care and love them, whether they may appreciate it or not. Be there. They will come to realize what a friend you've been.

Tips

* Listen to what they have to say and let them know that you are there to help if
needed.
* Be happy yourself. You're saying, I know how to be happy - follow me! It can
fade their sadness, getting in touch with their desire to enjoy themselves
instead of shedding tears.
* Do something that encourages sweating. Football, soccer, basketball, a jog with
you two together, dancing, bowling, cleaning up the garage, etc.
* Give your friend a hug! Tell them how you feel about them.
* Take him/her to see animals, especially when he/her loves them!
* Do something that is familiar and entertains him/her.
* Let them know that you're comfortable with them around - say "Vera! I love
you!", "I missed you!", "I love being around you!", "It's so nice to be here
with you", etc. The other person would appreciate knowing that they're
appreciated! Say anything sweet you truly mean, but have always kept on the
inside. It'll make them smile physically and mentally, knowing that it came from
the bottom of your heart.

Warnings

* If your friend wants to be alone, leave him or her alone.
* If your friend is upset about someone, don't say bad things about that person,
to make things worse. It'd just encourage negative feelings towards that someone
he/she is thinking of.
* Try to avoid making comments about how you pity him/her.
* Don't try too hard to cheer this other person up, meaning trying for a long
period of time without any success. If you do, they can start thinking that you
can't make them happy.

Source : http://www.wikihow.com/Make-Someone-Happy