1.  Put your sling on, shoulder fabric cupping your shoulder, rings positioned above the corsage position. Pick up your child.
2.  Get a good grip on your child's legs and back, supporting the neck of very young babies, and hold the child against the shoulder without sling fabric .  With larger babies, you will be tipping the child over your shoulder, great fun for easily amused toddlers.
3.  Place your baby's body in the sling, pull the sling body fabric over the baby's bottom as you thread the baby's legs through the sling; 
4. Hold the sling body and baby with one arm, get a good grip on your rings, and scoot the baby and sling so that the baby rests just above and over your hip.  Use the baby's bottom as a handle (not the baby's shoulders.)  The baby's bottom must be firmly seated in the sling and there should be enough fabric on the baby's back to hold the child in place if he or she tips away from your body a bit.  The baby's knees must be higher than rump, fabric spread as close to the baby's armpits and knees as possible.  The baby's legs will straddle the side of your body.  If the ring sling feels too loose,  lift up the rings to adjust it.  Generally, the heavier the baby, the higher above your hip bone the baby rests. 
Carrying a baby on your back:
Leah's thoughts on this postion:
For people who get the knack of the back carry, it's a truely useful position.  I, however, never really have enjoyed it much until my child wsa ~2.5, very experienced with a sling and old enough to enjoy the walking rhythm unique to back carries.  If the baby is at all squirmy, it's just not fun or safe and I get uneasy because I can't see very well how the baby is positioned.  However, under the right conditions, the back carry is wonderful.
I've found a postion on my hip with the baby scooted behind my arm but not quite all the way to my back to be very useful on occassion, too.
Leah's thoughts on this position:
As a baby gains core strength and can sit up for extended periods of time, you can begin babywearing with the baby on your hip.  For most people, the hip carry is truely the most useful babywearing position of all because it coincides with the time when your baby starts to be really heavy to hold unasisted.  Many babies are carried in the hip carry from around 9 mo's, some as early as 4 mo's, all the way through toddlerhood.
*Babies on your hip have an extraordinary reach and at hip level, they can get ahold of almost anything you can.  Light switches are a very popular target.
*Make sure your baby can't lean too far from your body...some children have a tendency to swing out a bit and crack into doorways.
*Soft shoes, bare feet or feet in socks make it easier to tuck a larger toddler's feet through a sling.
*Switch shoulders for prolonged babywearing.
*Use your arm opposite of the sling rings to temporarily block a baby in the hip carry from getting a hold on something in front of you (lift your arm over the babie's head, such as in the first picture of the back carry instructions below.)
*Unfold the fabric layer at the rings to better distribute the weightload.
*Consider wearing the sling with the rings on your back instead of your front....the sling will have a snugger fit (more like a pouch.)

Carrying a baby on your hip:
Copyright 2006:  Sweet Things Baby Slings, LLC.
1. Start with your rings behind your shoulder, toddler tummy-to-tummy.

1. Start with your rings behind your shoulder, toddler tummy-to-tummy.
2. Position toddler on your hip.

2. Position toddler on your hip.
4. Reach your arm in front of the toddler and scoot the sling/toddler behind your hip.

4. Reach your arm in front of the toddler and scoot the sling/toddler behind your hip.
5. Scoot your toddler to your back. Bending forwards helps but is not good for your health. Several small scoots of the toddler's bottom, with the babywearer standing upright and minimizing twisting of your back, is better.

5. Scoot your toddler to your back. Bending forwards helps but is not good for your health. Several small scoots of the toddler's bottom, with the babywearer standing upright and minimizing twisting of your back, is better.
6. Check in a mirror or ask another person to make sure your toddler is still securely seated in the sling (fabric spread between knees and back.) Spread fabric over your breast and ring-side shoulder to make yourself more comfy.

6. Check in a mirror or ask another person to make sure your toddler is still securely seated in the sling (fabric spread between knees and back.) Spread fabric over your breast and ring-side shoulder to make yourself more comfy.
7. And off you go! The child in this picture is 3 yrs. old & has been in slings all her life. A younger or less experienced baby probably should be positioned with the top rail more snug to bring the baby closer to your torso.

7. And off you go! The child in this picture is 3 yrs. old & has been in slings all her life. A younger or less experienced baby probably should be positioned with the top rail more snug to bring the baby closer to your torso.
Click on images for more detail; click again for a slideshow.
Ring Slings:  Using the Hip & Back Carries.