I was never much good at bending down with them in a sling, back or front so didn't get a lot done while carrying them. Back carries were slightly better for me as I could at least things in front of me.
We only have a small garden so it was not to bad to carry out something out to contain the little one, I;m not sure I would want ot lug things too far. We did take the pack and play out there sometimes, especially if the grass was still a bit damp. My kids loved it if I stuck the ball pool balls in it, otherwise once they were crawling they wanted to be out and about.
Like the PP we used the pushchair in various places they were happy to nap in in after a bit of a walk around or sit/lay and play, we had a toy bar with a couple of dangling toys which kept them busy when they were small. Again once they were crawling they were not so happy to sit.
Once they were able to sit we got a swing with a bucket type seat. DD would sit in that for quite a while with the occasional push.
By the time they were walking they tended to come and "help" me. I remember DD spending ages collecting leave/twigs/stones in her little wagon.