You should be able to collect 20 signatures an hour. If you're not, consider changing locations or ask another volunteer to listen to you and make suggestions. Be as clean and neat as possible. After a person has signed, check the petition and make sure it is properly filled out before the person leaves. Try to approach groups of two to four people.
Larger groups are harder to convince.
It is usually easier to get younger people to sign than older people. If you have a choice, go to the younger person. For some reason, petitioners consistently report that black females will sign more often than other ethnic groups. You may often have to say this twice to get people to the point of signing. If you get one person to sign, stop someone else and give them the pitch while the first person is signing.