I started back carrying DD1 at 6 wks, but our nanny had her in the front in the Ergo until 8 mths. I FWCC pretty consistently until about 6 mths. I think because I got the hang of putting her on my back when she was tiny it wasn't so hard as she got bigger, plus she cooperates and hangs on the right way! But I do know bwing mamas whose babies were older when they started and became pros.

Now she's a toddler I prefer back or hip carries.