Lying Down
This is the most natural position for many people and probably the easiest for beginners. Just roll your partner onto their stomach and start nosing around their bum or licking the small of their back. Before you know it, you'll be down in the valley. For a better angle and access, have your partner raise their hips slightly and slide a pillow underneath their pelvis. This will raise their butt up and make their cheeks easier to spread. This may progress naturally to them getting up on their knees in a kneeling or crouching position, pushing their ass eagerly into your face.
Yoga
These positions work well if your partner is athletic or limber. The recipient lays on the bed and assumes a shoulder-stand position (legs and torso in the air, with weight supported on the neck and shoulders). With their ass pointing up, you can kneel upright on the bed and bury your face in it from either side. If you position yourself near your partner's head, they can rest their legs or knees on your shoulders.
If your partner's spine is really flexible, they can expose their ass to you fully by placing their feet on the bed above their head, or even placing their knees on either side of their head. This is also a perfect position for guys to attempt autofellatio.
Standing
If the person to be eaten is standing up you can crouch down behind them. Here you have easy access to raise your hands and separate their cheeks for a clear shot to that puckered hole. Many people find crouching for any length of time to be uncomfortable. Try sitting in a chair and have your partner stand in front of you with your knees between their legs. Now you have the same access, but because you are sitting in a chair, you have far more leverage to get into some serious eating.
Another variation on the standing recipient is to have them put one leg up on something -- chair, a step, the edge of the bathtub. It all depends on what's handy where you happen to be. The raised leg not only helps separate the cheeks for you, but it exposes the perineum for your tongue to tend to.
Bending Over
If your partner bends over while receiving, it give you a more straightforward angle to approach their hole. Instead of having to tilt your head so that you are coming up from underneath, you can aim directly for the center of their vertical smile. You also have an easy reach to fondle his testicles or her clit.
Try having your partner lean over something that is more than waist high so their feet dangle just above the floor. A kitchen counter or a porch railing often works well for this. If you do happen to be in the kitchen, try covering that ass with whip cream before you start eating. Add some chocolate sauce and nuts and you'll have a butt sundae.
Sit on My Face
Lay down on the bed with your head laying back over the edge of the mattress. Have your partner back up and squat down onto your face. When they become tired of squatting they can lean back and lay across your body. This is an especially good position if you like to do the eating. With your partners ass shoved so tightly to your mouth, you feel compelled to work your tongue in as deeply as is humanly possible.
The other variation is the always popular 69 position, where one partner squats over the other, and the partner on the bottom raises their knees up to allow access to their hole. This way you can eat each other's asses. And if you don't want to argue over who's on top, try laying on your sides and bend around until you each have your faces comfortably in the other's crack.
