I see giving head as an artform. Like anything, if you hone in on the details and really scratch beneath the surface, oh boy, your blowjob-game will elevate significantly. Anybody can suck a dick, but not everybody can give unforgettable head.
I'll share something personal and erotic; I've never NOT made a guy cum from sucking his dick. Maybe re-read that. Hey, I mean business. It's the truth and I'm proud of that. Without going into numbers, I'll confess, I've sucked a lot of dick.
I start by expressing to a guy that I'd really love to suck his dick. This instantly puts you above many. Here, you're explaining your love of it. Plus, if delivered correctly, it sounds rather cute.
I'll remove a guy's clothes and kiss around his boxers. Acknowledging pre cum and encouraging it. Complimenting the bulge, as after all, it's for me. Running my hands up and down his stomach, or perhaps kissing his inner thighs. It's time I got it out, don't ya think?
When I get it out, I worship it. I'll tell him at least one thing that I LOVE about his cock. Each guy always has a defining characteristic. It could be gorgeous curvature. It may be the sheer length or (partially intimidating) girth.
I welcome any cock; whether it's challenging, scary, cute, or as I often liken it to - a rollercoaster. Yeah, the type that you're excited as hell, yet a little like, "oh fuck!"
I'll tie my hair up, indicating I'm in this for the long haul, even though these tactics can ensure a quick finish. I'll plant sloppy kisses on his head. The more slobber, the better. Wet, sloppy head is the best head.
Let's assume I'm submissively on my knees. I'll lick the shaft. I purposely haven't removed my clothes yet. This IS about him, but I'll be showing off my chosen asset shortly.
If it's big, I'll tell him, "omfg that's a definite two hander." Or, I like to compare it to my forearm. Guys LOVE that.
I'd recommend implementing a philosophy of, 'firm grip, loose fingers'. Take that in a moment. Running the fingers over the extra sensitive head is toe curling.