How do you get confident talking on the radios?

I’m a student pilot and have always struggled with confidence talking on the radio. I know everything I have to say and the order in which to say it, but every time I key the mic i feel like I freeze up and forget what to say. I always wind up leaving out a word or two or messing up pronunciation, or just getting tongue tied. My instructor always says it’ll come with time and that it’s completely natural. But is there any tips or advice on how to get over that fear of messing up?