Getting here
This is one of the best-connected parts of Brooklyn, which is easy to forget because no single station serves all of it.
Fort Greene and Clinton Hill sit just east of Downtown Brooklyn, and the transit picture reflects that: a lot of lines pass close by, but they arrive at different edges of the neighbourhood rather than converging on one point.
For BAM and Lafayette Avenue
The C at Lafayette Avenue is the closest stop to BAM and to the corner of Lafayette and Clermont, and it is the one to use for the Masonic Temple — a walk of a couple of minutes.
The G at Fulton Street is the other close option and is the useful line if you are coming from Greenpoint, Williamsburg or Carroll Gardens without going through Manhattan.
For the wider area
Atlantic Avenue–Barclays Center is the big interchange a few blocks south, and it is worth walking to. The 2, 3, 4, 5, B, D, N, Q, R and the Long Island Rail Road all reach it. From Manhattan, this is usually the fastest way in even though it is not the nearest station to most of the neighbourhood.
DeKalb Avenue (B, Q, R) sits on the Downtown Brooklyn side and is convenient for the western edge of Fort Greene and for the Brooklyn Paramount.
For Clinton Hill, the G at Classon Avenue or Clinton–Washington Avenues puts you on Lafayette near Pratt, and the C at Clinton–Washington Avenues covers the Fulton Street side. Note that there are two differently located stations with almost the same name, on the C and the G — check which one your directions mean, because the walk between them is not trivial.
Buses
The B38 runs along DeKalb and the B25 along Fulton, both of which are genuinely useful for east–west trips that the subway handles badly. The B69 covers Vanderbilt.
On foot
The neighbourhood is small and walkable, and the grid is legible. From the Lafayette Avenue C stop you can reach BAM, the Masonic Temple, Fort Greene Park and most of the Fulton Street bars inside fifteen minutes. Walking between Fort Greene and Clinton Hill along Lafayette or Myrtle takes about ten.
Service changes on weekends are frequent on the C and G in particular. Check before you rely on either late at night.