I've had some neigbor's do this exact same thing your talking about, ages (15,16)
Hints: (the more thought, you put into the more likely people will look at you as really putting in an effort to do a good job, First impression is everything)
Make a flyer, handout, or some kind of brochure
Give yourself a name, (ex: Brian's Yard service)
detail what you'll do:
Rake Leaves / bag leaves
Clean out Pond
and so on
give prices for each thing, and negotiate on the more involved stuff
be sure to say price using your bags if your doing that , or give a discount for them to provide bag $5.00 you bag ($4.75 theirs)
Definitely know the trash guidelines for leaves, or find someone who wants them for mulch, recycling
Then just go around the neighborhood, knocking on doors to speak to someone explain what your doing and give them a handout or put in mailbox with contact info on it
around here (WV) we have tons of leaves and the guys made enough to hire a third guy to help and they each made a good deal after their expenses..
Best of Luck To you