Everyone likes to be smiled at. It doesn't matter if it is a man or woman doing the smiling either. Its a friendly thing to do, and a great way to make a good first impression. I try to smile when I make eye contact with anyone. Not all of them smile back. Some might be thinking about some really upsetting stuff. Others are just too shy to smile back. A lot of other people do, smile back. In fact, a smile can be contagious. You might see that same person smiling a few minutes later from where you put them in a good mood. I say go for it. If that is your picture on your profile, why would you think anyone would find you unattractive?
If you have any intention of talking to me or having me talk to you, smiling is the most basic step to get there. If I walk past a girl and smile at her but don't get one in return, that's an immediate sign she's not the slightest bit interested in talking to me. Not only does it say "She's not interested in talking to me", but it also says "She's an unpleasant person".
Also, as far as I'm concerned, girls look better smiling, period. I've looked at tons of girls who I've thought "She'd be pretty cute if she was smiling", but I have yet to find one that I thought looked worse with a smile on.
Smile. It makes you more appealing and it makes you look better.
I personally feel the best thing about a girl is her smile and if a girl smiles at me I kinda like it and I would definately smile back ,no matter what,so go by your instincts so if you feel like smiling then definately you must smile without thinking too much.I believe if a person smiles at someone that shows the character of a person.So if you smile at me I would think you are a good girl.So if someone doesn't smile back I would think that the person is rude or depressed.