Always keep in mind what passers-by see only a few seconds. If you highly complex about appearance, keep in mind that the people who meet you for the entire day in the subway, on the street, in a cafe, no matter you. They can, of course, to pay attention to your "funny" skirt, hairstyle, purse, etc., but the likelihood that they will remember her whole life and made fun of you, miserable.
To verify this, try to do something unusual for your lifestyle and behavior. As a rule, such actions react only close people or those who knows you well. And the rest of the people around will still. People are too busy with their daily problems, to laugh at you all day, month or year. After all, that's how much time you can't forget someone's sidelong glance in a tram or a cafe.
Love yourself. If you are afraid of each opinion, it speaks of low self-esteem. You like your clothes, occupation, interests? If all this does not threaten your health, safety of others and is not contrary to law, it is the place to be. You want to be a librarian, and the friends and the spouse(-and) insist on the career of an entrepreneur? Listen to your heart, not someone else's stereotypes about the prestige and social status.
Focus on your best qualities. This will make insecure person charming and interesting personality. Daily work on yourself, praise yourself even for small successes. And don't forget to smile. Remember, that there are millions of people living under the imposed stereotypes. And if someone tries to stab you with a look or a word, rather, he wants to establish themselves at your expense. In this case, the answer is to apply sense of humor or mentally take a notorious bully, and then completely forget about what happened.