I always offer my assistance when I see someone at my apartment complex carrying groceries, especially if it's upstairs.
I've offered this often enough to realize that many people have a hard time accepting free help, so to increase my chances of them accepting my offer, I changed my pitch from-
Can I help you with your groceries?
to
Hey, if you don't mind I'm going to help carry your groceries and just set them down on your front porch, okay?
Harder to turn that down.
Also for years I have been involved in my apartment complex community simply by being outside with all the kids. I know all of their names, know most of their family and their backgrounds, have their parents phone numbers, and I "dad" the kids when I see them misbehaving like bullying or coping an unjustified attitude. I have zero problems telling a kid he cannot play football with us anymore today due to his attitude/actions.
That last part may not seem "good deed of the day", however I have the utmost confidence that by me trying to teach these kids life lessons, they will respect me for it and perhaps try to be better individuals themselves.
Also when we're playing two on two football, I always throw the ball two times to my son, and two times to a kid who isn't my son. I'd like to throw it to my sons every play, but I've got to be fair.