He lays on back on the bed.
You have knees flat on bed.

Position yourself a nanometer above his nose.
Usually without contact.
Don't move.......ever.

Risk of acute boredom after the first 30 seconds.
You may also need both legs amputated due to loss of circulation.
But he will enjoy it.

every time I've done face sitting it's been actual sitting. Bit of up and down teasing yes, but essentially face SITTING, controlling his breathing by sitting on it and grinding, then being still. Lifting up to allow him to breath again, hovering tantalisingly close to his face, then plonking myself down again.

LOL  They all spin a different angle on their perve I guess.

Each time I've done it they've specify no contact.
It's actually a lot easier your way sitting.... rather than poised, hovering.

Hmmmm mine has also been actually sitting on the face, but i tend to have them place their heads at the edge of the bed which makes it easier for me.  If they want to bum i am also able to easily turn around  and place my knees on the bed and lower my bum over their face.

There is different types of face sitting or queening/breath control out there, I never get naked, I have a few clients who request different types of face sitting scenarios but cunniligus is never involved in my sessions.

The nearest they get to 'a lick' is when I wear knickers, but can't remember the last time I I did a session with just knickers, usually jeans, latex or leather pants/trousers, hot pants or leggings...but in my case they are usually chained/handcuffed to my BDSM mat so they can't move plus CBT is usually involved, and as cheesy peas suggested your in control and nanometer away from there nose is usually best then Squash so they can't breath or move their tongue, even better when they wear a gag too! But unfortunately you do have to let them breath .......occasionally!