IMO, the best part about giving blowjobs is that they allow you, the giver, to feel sexy and desired. I used to have an aversion towards giving them, but a few things helped change that for me:
Try making a video
One time I did my make up real nice, attached a dildo to a wall, and filmed myself with my phone while practicing a blowjob on said dildo. I afixed the phone to the wall using a stand and some duct tape, so it would film from the perspective of a the 'man' receiving the BJ. I tried all the 'tactics' to make it look sexy: some seductive foreplay/building up sexy tension, making occasional eye contact, deepthroating, breaking suction to smile occasionally... And upon reviewing the footage, I was blown away by how sexy it made me look. Gave me an immediate confidence boost. Now I love giving blowjobs, because they let me relish in how sexy I feel.
Stick to BJ's as a foreplay rather than the main course
Most men have a hard time trying to ejaculate from just a blowjob alone. That is not your fault; even a perfect blowjob can be harder for a man to ejaculate from than just regular old intercourse. So just ask daddy to progress to the next sex act when he sees you getting tired/struggling to keep it up. Blowjobs are hard work and often exhausting, that goes for everyone, even for those women who can make them look easy. But you're working for a good cause, and if your partner is decent he will always reward you for them.
Get your partner to communicate
Every guy like his blowjobs a little different. Some people like a very strong suction field and just plain repetitive sucking motions -- those are hard to keep up and can leave your jaws feeling sore. Others want to push the back of your head into a deepthroat position (where maintaining suction is impossible), and yet others want you to be very light and gentle with your lips, more like massaging the penis rather than straight up sucking it. Each style requires some practice, in order to get in tune with how your partner likes it.
Blowjobs are kind of like a stage a performance. They can be whatever you make them.
Blowjobs can be both an act of submission and dominance. You can play the part of the submissive little girl, degrading herself for daddy's pleasure and getting her face sexily ruined, etc. And once you've gained some skill in them, you can also take the lead and feel like a confident femme fatale, a desirable seductress, a sex goddess/pornstar, whatever. Whatever feels fun for you. Lose yourself in the fantasy of them.
Oh, and one more thing: DON'T BE AFRAID TO FUCK UP. IT'S OKAY TO STUMBLE OR GIVE A BAD/MEDIOCRE BLOWJOB ONCE IN A WHILE. Especially when you're just learning how to do it. A good dominant takes pleasure out of seeing your progress, trying things outside your comfort zone. A good dominant wants to guide you towards greater self confidence and sexiness. What's there to guide if you already know how to do everything ?