One of your biggest expenses can be arriving by air, but for the seasoned traveler there are indeed cheap options. Keep in mind that if you are travelling in a group of four or five people, it's possibly cheaper (and certainly wiser) to take a taxi (even from Newark), especially if you have a lot of luggage. Four or five of you can share a taxi from LaGuardia to Midtown Manhattan and probably will pay $8 each or less, depending on your destination and time of day. If you are tired or it is late at night, do spend the money on the taxi, for it is the safest option. But taxis from JFK and Newark are really not options for the road warrior or backpacker.
Seasoned travelers and professional money-savers from India to Brazil know the way to get into cities by bus, and New York City is no exception: You can get many places from LaGuardia airport for just $2, the standard bus fare. But it is a more complicated situation at JFK. Because the free shuttle buses between JFK airport and the Howard Beach "A" subway train were eliminated, you essentially are locked into either 1) taking the AirTrain for $5 to get either to the Howard Beach "A" subway station or to Jamaica station ("E," "J" and "Z" subway trains and Long Island Railroad), or 2) taking the slow Q10 bus to connect with the A, E, J or Z train. There are private buses (coaches) that go from JFK into Manhattan, but unless you arrive at midday, on a weekend, or late at night, the AirTrain and subway combination is generally more efficient—and cheaper. Meanwhile, at Newark, if you have time and patience, you could take the NJ Transit #40 bus to Newark Penn Station and transfer to the PATH train to Manhattan. This will cost you a total of less than three dollars!
Late at night and on weekends, subway construction can sometimes add an extra 30 minutes to your travel time—opt for the bus or AirTrain plus discounted Long Island Rail Road $3.25 City Ticket instead. We are guessing you already know all about MetroCard, but if you haven't been to New York City before, do note that transfers from bus to subway—and vice-versa—are free. But only if you pay with MetroCard! If you hop on the bus at the airport and pay the $2 (coins only, no dollar bills), you can get a free bus transfer but not a free subway transfer. Note: Metrocards are generally impossible to find at LaGuardia and JFK airports. Also beware of touts hanging around the luggage carousels at JFK who offer you impossibly low limousine prices to Manhattan. While indeed you could possibly get a $35 bargain trip, unless you are a seasoned negotiator your fare might suddenly rise upon reaching your destination. You've been warned! We also remind you that tolls and tips are not included in a limousine price quote—so plan on on up to $15 additional.
Thus, we suggest you have a good look at our airport page for JFK, LaGuardia and Newark airport transportation options, and consider your alternatives based on what time of day you arrive. The choices are many.