Your smile will give you a positive countenance that will make people feel comfortable around you.
If you're trying to achieve, there will be roadblocks. I've had them; everybody has had them. But obstacles don't have to stop you. If you run into a wall, don't turn around and give up. Figure out how to climb it, go through it, or work around it.
If you smile when no one else is around, you really mean it.
A lie can travel half way around the world while the truth is putting on its shoes.
Make it a habit to tell people thank you. To express your appreciation, sincerely and without the expectation of anything in return. Truly appreciate those around you, and you'll soon find many others around you. Truly appreciate life, and you'll find that you have more of it.