Deep throating?

I've always had a problem with my gag reflex and I can't go any farther than half way down my SOs shaft. I'm wondering if any of you girls have suggestions as to how I can deep throat and not feel like I'm going to throw up. I really want to impress my guy and show him a good time. It's my own decision and not his, he honestly doesn't care about me deep throating. I just really want to make him feel great! Xx