Obviously, you’ll never be able to control what people think of you (trust me, I tried all throughout my 20s), but you can do your part to shape the perception of you to one that is positive, enduring, and authentic.
And that brings me to the most important tip yet: be yourself.
It sounds cliché (because it’s become a bit cliché, unfortunately), but the sentiment remains true. There’s no point in making a good impression if it’s one that you can’t maintain; if it’s one that isn’t true to you.
Do your best to prepare and present your best self, but make sure it’s just that—your self.