How do I get better at?

at verbally standing up for myself?As I don't do it enough and let people get away with comments and snide remarks to me and rude people have started arguments with me in the past and I have not said anything baCK TO THEM.I am a nice person and just look to get on with everyone but sometimes in Life I have come across rude people like one time when me and my friends were going into a club and a bouncer said some comments to us, I said nothing back but my friend stood up for himself - how do I get better at standing up for myself?As it just doesn't seem right and logical to take things off of people when I don't do anything to anyone just keep myself to myself and mind my own!!!