Stop selling people on who you are. They don't care- that is unless you're Iron Man. Sell people on who THEY are. Yes, your first impression shouldn't be about you. You need to make the other person feel like it is all about them. Even if you say very little, if you can make the other person meeting you for the first time feel like they are the only human on planet Earth- you will have a fan for life.
Don't try to make a sale. Don't pitch yourself in anyway other than minimally. Learn about that person, be polite and helpful. Make the other person feel famously special. Once you do- you have nailed the first impression.
It is important to practice this technique. Sometimes it can come off as condescending or not genuine. You don't want this to backfire.
Try practicing the next time you meet someone. I promise you that with practice- this secret will help you better navigate your personal and professional life.