This is not something I have managed to do - someone who you can just relax with, talk to, phone up for a chat - see without children!
Toddler groups are not conducive to conversation and "playdates" (hate that word) are not satisfactory either. It is all about clicking with someone and I have not. Yes I know people, talk at nursery gates, see people for tea/play 2 or 3 times a week but no close friends.
Is it something you managed to do with babies/toddlers or only when your children were a bit older?