The key to a good juicy burger is to get quality meat, and to make sure the fat content is higher and to not use lean ground meats, especially if it is for a beef burger. You want higher fat because that is where the juice and flavor is. I also highly recommend either going to a local butcher or going to a community market that sells locally raised meat.
Oh, don't forget the BACON..if you're eating burgers without Bacon, you're doing it wrong lol :)
Click here for this recipe: https://www.prairiewindslife.com/recipes/bacon-jalapeno-guacamole-burger