Do you want to put a smile on someone's face today? Maybe make their day a little better. It won't cost you a single penny or much time to do just that. And because smiling is contagious, it probably won't just be one person you make smile today.

Here are 20 ways to turn that frown upside down.

1. Send some flowers to your partner at work.
2. Compliment a friend or work colleague on their appearance.
3. Donate something to charity.
4. Take a friend out to lunch.
5. Let someone know you miss them.
6. Make a surprise telephone call to your partner at work, just to say hi.
7. Hold a door open for someone walking behind you.
8. Hug your partner for no reason.
9. Leave a joke on a friends answer machine.
10. Send a card to a friend letting them know what a good friend they are.
11. Give up your seat on the train to someone when there aren't any left.
12. Share your umbrella on a rainy day.
13. Ask a friend if they need anything while you're out shopping.
14. When it's raining, plan an indoor picnic with your children.
15. Leave a love letter somewhere where your partner will find it.
16. Send someone an unusual and unexpected gift like chocolates.
17. Tell your child you're proud of them.
18. Tell someone you thought about them the other day.
19. Cook a surprise meal for your partner one night, especially if they normally do the cooking.
20. Tell your partner you love them.

Did you know it takes only 17 muscles to smile, but 43 to frown. Why waste all that energy frowning when you could just smile.

Here are 5 more facts about smiling.

1. Women smile more than men.
2. Smiling releases endorphins that make us feel better.
3. We are all born with the ability to smile, it's not something we learn from others.
4. A smile is a universal expression of happiness.
5. A smiling person is thought to be a more pleasant, attractive, sociable, sincere and competent than a non-smiling person.

Just remember, smiling is the easiest and cheapest way of improving your looks.