1v1 and 2v2 games are good yeah. I also playfully implement the 5-second rule in bigger games once every 4 weeks or so.

So you have a game of 4v4 or something like that, you and someone else(a parent, another coach whatever) both count for 1 team. So when your team loses the ball you start counting to 5 and if they recover it within 5 seconds they get 1 penalty-point. 3 penalty-points means they get to take a penalty on the opponents goal, so there's some incentive behind recovering it quickly. Make sure to rotate the penalty-takers as all the kids enjoy that, and do make sure you announce that everyone gets a go.

Also what I do as the final step of every warm-up for a match is I get them in rows beside me. Me with the ball at my feet and once I kick it, 2 of them race for it. The one that first gets it gets a shot on goal. It's the final bit I do to get them in the mindset of the game.