Your topic should be small enough to be manageable -- you will find it far easier to do fieldwork on "Holiday Customs in my Italian-American Family" than on "Italian-American Folklore." "Children's Games in South Buffalo" is a more workable topic than "Children's Folklore." I would suggest concentrating on a single group (folklore of workers at Widgets Manufacturing, folklore of Serbian-Americans in Lackawanna, folklore of theatre majors at Buffalo State College) or a single genre (weather beliefs, Halloween customs, urban legends).
You can save a lot of time by doing fieldwork among people with whom you spend time on a regular basis: your family; your fellow employees; the members of your rugby team, the congregation of your church, synagogue, mosque or coven; the "regulars" at your favorite tavern, or the members of your Creative Anachronisms group. The context of the folklore will also be familiar to you, which will make writing your analytical essay much easier. I suggest that you not pick a topic that involves travel or other unnecessary expenditure of time or money. Some groups are more closed to outsiders than others. For this reason, I would suggest that you not attempt to do fieldwork among Native Americans or the Amish unless you have close friends or relatives in those communities.
There are some topics which are difficult to work on simply because folklorists haven't written about them and it will therefore be difficult to put together a bibliography. For example, there is almost nothing written about the folklore of musicians, although musicians have a lot of folklore. Students who have worked on this topic have had to look at dozens of biographies and autobiographies of musicians to find comparative material. Some students don't mind doing this, others would prefer to choose a topic such as Halloween customs or urban legends, about which a great deal has been written. When you send me your proposed project topic, I'll let you know if the bibliography will present special difficulties.