I used the monkey wrap with my son when he was born and when he was big enough, an Ergo baby carrier. He was in it a lot because we were very active out and about with my three year old. I even breastfed while he was in the monkey wrap. Not the best but worked when we were out and about.
I also used a Moses basket on my counter at home in the kitchen so he was up out of the way from the older children. This worked well until he was more aware and then he could go in the swing or playpen.