Oral sex- There are how to or instructional videos for people who want better technique. There is room for improvement and there are no really great ways to have that particular conversation. Bragging about your sexual prowess is similar to the salesperson who over promises and under delivers. Be humble and ask what they want/need/ prefer and be open to improving your technique. Be aware that men and women like different things at different times and even if you were just sexual, it might be different now.
There are cards, articles, books etc for the technique part. What most people talk about is “Don’t approach it as a task or a chore.”
If you are going to ruin it with attitude, don’t do it. Ask them what they want and explore, get creative. You want your partner to feel good and look forward to being with you and to desire you, right?
Talk about what you like in terms of duration of oral pleasuring, what you prefer with position, variety, changing positions, be creative, duration, humming, eye contact, smell, strength of suction, speed, intensity, hands, no hands, kissing afterwards, intercourse before oral, after etc.
People are terrible at mind reading. Don’t bait and switch, apparently a common complaint. Don’t agree and make it seem like you enjoy oral sex just to “get” the person and then once you’re securely together, stop doing it. That’s not fair.
Hygiene is vital. Shower and wash (with soap) before doing this as a matter of respect to your partner.
There are smells that can be a big turn off and reduce the likelihood of it happening in the future. Yes, Pineapple works for smell and taste and asparagus negatively affects taste and smell. There are articles you can search for these hints.
If you don’t want to do it at all, be upfront with that and why.