dont let randoms bother you, you dont know them, they dont know you, and most importantly, they dont know Allah, If they clearly just want to mock islam, let them, because if you get angry and say something rude, it will only assure them Islam is as they envision, instead ask Allah Hiddayat for them, and thank Allah for making you Muslim. After all, in this world Islam is the biggest gift of all. Jus imagine, god forbid if you weren't a muslim, you could have been one of them.

If someone comes up to you and genuinely seems interested in Islam, explain to them nicely. Try not to get all emotional and deep, people tend to back away then.

Just remember, you have Allah on your side and they dont, NOTHING that say can get to you. I used to get really angry when people would laugh or point at the my hijab, but now humdullilah i dont let it bother me...

hold your head high and ignore. trust me it seems hard at first but you'll get used to it...