How to Create an Ergonomic Seat in a Sling or Wrap
Keep in mind that babies naturally go into a spread squat position that looks like an "M" shape (with the knees above baby's bum). You want your sling or wrap to facilitate that position. To easily create an "M" seat;
1.) Welcome the baby's legs through the carrier and have them sit on top of it like a swing.
2.) Pull the top 1/3 of the carrier over the baby's back. You want enough fabric to cover their head (but don't actually cover their head.)
3.) reach under the baby's leg, grab edge of the fabric under their bum and spread it from one knee to the other and up toward their belly button.
4.) tighten the carrier in at least 3 sections starting with the top edge, middle, then bottom edge. (With a ring sling you will be able to tighten with one hand but with a wrap you will need to tighten with one hand and hand it to the opposite hand as you go along)
5.) If using a wrap, tie your carrier to secure it. Finally as with all babywearing check that baby is visible, kissable and that their chin doesn't touch their chest.