How should I propose to my longtime girlfriend?

I’m looking to propose to my best friend, my girlfriend. I can’t afford a crazy expensive ring but we love each other very much and we’re pretty big on making treasured memories. I’m blessed to have a woman in my life who isn’t materialistic at all. I wanna make the best, longest lasting impression as possible. I know there’s no set protocol but I’m curious as to how you jellies feel about this. I’m 31, she’s 34 and she has a 12 year old son. How do you guys think I should do it? And how should we tell our parents? Should both of us be present?