I loves the bare-breasted blow job. A pendant breast, tight nipples and smooth rounded flesh to fill in the peripheral sensorium is like chocolate on my bacon - better and better.
That being said, a hot blow job with eye contact, quick response to direction and that hot-hot question of "How do you want it?" when I am approaching blastoff is a beautiful thing even when my fellatrix is fully dressed.
But for the OP, I think my preference is to lie either prone or with my upper back and neck propped on pillows while the
topless/nude Giver of Head (GOH) either kneels between my thighs or is reclining beside me. The kneeling position is exquisite because her breasts have gravity working for them not against them. The reclining position is also a lovely one because I have her entire body to fondle/ogle.
Not to go too far off topic, but a very nice refinement of the blow job was the numbering of half a dozen favorite techniques. Which means that I can ask for a slow 1, and then tell her to 6 me. Or 4 - I like 4
There is room for growth in this system, and to avoid confusion the different cowgirls have been given letters. When she runs through her ABC's and then does me by the numbers I am a very happily exhausted and completely satiated fellow.