Try different carriers and keep in mind as baby grows the carrier that works best may change.
I keep a sling handy if DS falls to sleep on me and I need to get up and pee, I can get the sling around us without waking him normally so I can get up and have my hands free enough to manage a few things. But as he has grown, I wouldn't want to wear him in a sling for very long since it is hard on the back, and shoulder. If I expect to be carrying him around for long or want to be up around and doing much while he sleeps, I've found the Ergo carrier is far better as baby approaches toddler and that even with my little guy over 20 lb now I can still wear him for miles of walking in the Ergo. If the Ergo is to pricy for you, look into a Mei Thai as an option.