If you come across as being unfriendly or boring, it will be very hard to change her initial impression of you (unless you happen to be blessed with the opportunity to work/interact/see her a lot after your first impression).

What you need to do, is to make sure that you are giving off the right signals.

There is a certain kind of energy that is given off by people who are friendly, confident and open - and it's super-addicting to those around you.

If you are positive and sure of yourself, it doesn't take long for people to realize it - and take note of you. Suddenly, they are much more open to spending time with you than they were before.

So what you need to do is smile a lot. Not a fake smile, but a REAL, genuine smile from way down deep inside of you.

Body language experts say that a real smile tends to cause little "laugh lines" to appear by the corners of your eyes (some people might call them crow's feet), whereas a fake smile doesn't.

Try it out in the mirror. Think of something funny and smile into the mirror, while looking at your facial expression. Then give just a regular smile while thinking of something sad - see the difference.

If you go around giving girls REAL smiles instead of fake ones, it shows that you're interested in them as a person, and that you're a really positive and confident guy.

So, you need to smile and be friendly. Especially when it comes to making good first impressions.