Back when I lived in the city and used a push mower with mulching blade to mow with, I used it with a bagger to gather the leaves. It mulched them down pretty good, then put them in the bag. I dumped the bag into the wifes flower bed and around bushes for mulch. Good for the plants and keep in the moisture and kept down the weeds and grass.
Now I just let them blow around all winter, dont have many trees that shed leaves, and in spring, they all get mulched up what isnt blown into the next county.