I do find that with my spirited LO it has always been about not wanting to be confined and wanting to have control over his own actions!
At 12 months he could walk, but not very far on his own without getting exhausted, and he did fall over a lot. So I didn't let him out tooo much, especially because I then had to hold his hands and push a buggy! So, sometimes I would take him out and walk ten steps forwards, ten steps back to the buggy and that was enough!
But, I didn't always have time for that, so I kept a massive bundle of toys and snacks in my nappy bag. I usually kept him rear facing in the push chair so that way I could still see him and chat with him and what not, and I don't know if that helped, or just made him bored faster? He could still see cars, trees, birds, and so on over my shoulder though!
Snacks are always a hit when he doesn't want to be in his buggy. Little tiny pots filled with cheerios and raisins are the best for us, although I do sometimes cut up bits of cheese and ham and put them in a pot. And bread rolls that I rip in half and he picks the bread out and hands me the crust when he is done!
Toys would get me a good 30 minutes, but I needed about 7 toys....he would play with them for 4 or 5 minutes and then thow them! One he did like a lot was a plastic toy phone that opened and played tunes when he hit the keys (it was a bright pink Barbie one much to DH's dismay!!! Was in the supermarket check out filled with candy, so until he learned how to get the candy out it was also a good shaker!)
But def snacks! (Oh just seeing now that you do the raisins and cheerios as well!!!! LOL!) I do often try to take him out when it is lunch time so that way he is actually getting food he NEEDS rather than just bribery snacks, but it does make his pushchair pretty messy!!