Tips for my boyfriend??

So I’ve been with my boyfriend for 2 years and he’s always loved going down on me but it just wasn’t enjoyable for me at first and now it’s just whatever. Idk if he’s just not going for the right spots, but any tips on how I can make it more enjoyable? I’ve mentioned it to him subtly but didn’t really catch on to it. Any movements or anything that maybe can make it better for me or just ways to tell him nicely that it’s not that good lol? He’s so sweet and I want to be nice about it.