Review instructions for putting on the sling.

Make sure the sling is tightened so that the pocket formed is above your waist and the slack is out of the back rail, but there is enough slack in the front rail to put baby inside.
Hold baby in burp position with head on the opposite shoulder as the rings.
Slide baby into the pocket of the sling making sure the back rail is between you and baby.

Fold baby's legs in a "froggy" position so that her bottom is in the sling and her knees are bent and against your chest.
Pull the top rail up to the back of baby's head. If there isn't enough fabric, shift the fabric that is in front of baby to behind baby, making sure that you still have some fabric between you and baby.

Support baby's bottom with one hand and with the other, tighten the back rail of the sling by pulling on the fold of fabric in the tail that is nearest to your shoulder.
Now tighten the top rail of the sling by pulling on the fold of fabric in the tail that is nearest to your chest.  Tighten until baby's head is supported.
For babies with head control, this position can be modified so that their legs come out of the bottom. 

To modify the position, instead of creating a wall of fabric against your chest, spread the top and bottom rails apart so that when you put baby in, the bottom rail will hold baby at the back of her knees.

Follow the above directions for getting baby in the sling.  Make sure the bottom rail covers baby to the back of her knees and the top rail is up high on baby's back, with her arms inside.  Spread baby's legs apart so they are straddling your tummy and lift her knees above her bottom so she is firmly and securely seated in the sling.

You can also use the method in the Instructions for Hip Carry to get baby into the sling.(hold baby first, put sling over the top of both of you.)
Tummy-to-Tummy Position
When finished, baby's head and weight should be supported by the sling and be above your waist. 

There should still be a wall of fabric between you and baby.  Check to make sure fabric is completely tucked under baby's bottom, feet, and legs.