( NSFW) How can I put out my best?

My girlfriend and I are going to have sex soon and I am on a—-maybe silly——quest to give her the best orgasm, but the goal is for her to say it or give a comment that suggests that when we are done. I was wondering if I could get some hands on tips from all you jellies that have experienced a mind blowing orgasm. Mainly tips on how to last longer.