Considered the plain standard way to suck off another guy, that isn't all that intimate, but good enough to get a mouth full.
Not imaginative, nor physically demanding, but oh so pleasing.
Both partners are in a prone position.
The Receiver (the one having their dick sucked) lays on their back, facing upwards.
They spread their legs slightly, to allow for easy access to their entire genitals.
The Giver (the one sucking the cock) lays facing downwards.
They position their body within the spread apart legs of the Receiver.
The Giver can use their arms, elbows, to keep their upper body off, or even use the thighs of the Receiver, for support, while engaging in the sucking.
One can use their hands, to grasp the penis, to stroke it along with their lips, or they can use their hands for some other exploration, of the Receiver's groin area.
Access to the rectal area is not all that accessible, but doable.
Primarily, it is the Receiver who receives the most satisfaction from this position, as they really have little to do, but enjoy the sensation of the Giver's mouth and hands.
They can provide assist though, by the occasional upward thrust of their lower body, to further aid in penetrating the mouth.
While they have limited access to the Giver, to provide any intimacy, they can reach the head, to help guide the force of the up and down motion.
For comfort, the Receiver may want to have a pillow behind their head and shoulders.
This will also give them a better view of their partners technique, and hey, it can be a real turn on, too.