One of the beautiful aspects of fantasy football is the presence of several different formats. From two-quarterback leagues to keeper leagues and daily fantasy, it's not hard to find a format that suits your personal taste.
If you're going to play with the same group of people year after year, dynasty leagues are one of the most fun and challenging options out there. You're not only drafting for the coming season, you're drafting players for the long-term—much like real NFL team do.
Therefore, it's important to emphasize youth and to consider what players' situations are going to look like in the coming years.