I was in Williamsburg just yesterday. Wow an Apple store where a pioneering bagle store use to be and formally Kings Pharmacy, a Whole Foods on Bedford and even a Corcoran Real Estate. Pretty soon Bedford will be like West Broadway in SoHo. LOL. Anyways I lived there when during the day people on the Southside basically stayed off the street before it was conquered by hipsters.
Anyways seemed like I saw mucho amounts of strange and odd looking people in the new Wiliamsburg.
On the weekend there is a FREE water Taxi Ride to IKEA in Red Hook just below the South Street Seaport. The ride is kinda brief, but I suggest having a a long lens like a 90. From Red Hook you can check out Gowanus and make your way back towards downtown Brooklyn.
I will say this: there are a lot of guns in Brooklyn, in Brooklyn there are a high amount of shootings for New York, and if I want to get shot Brooklyn is a good place to go where there is a higher probability than say Queens or Madhattan. I would also say probably a higher chance to be shot in Brooklyn than even the Bronx which is a much poorer borough.
To be safe here is the best advice: New York is likely the most safe large city on the planet. You pretty much can go early in the morning to even the worst areas and explore to really see the city, but very bad areas that are poor kinda change closer to dusk when all the riff-raft, drug dealers, and career criminals emerge. Kinda think of visiting bad areas and shooting when the underworld is sleeping. Definately some areas change drastically at night and clearly are not safe.
I do not like neck straps, but if I use one I wear it bandeleer style so that I am less vulnerable to getting choked. I also like to keep my hands free and to not be burdened by lots of gear. I tend to carry my camera in my right hand using a wrist strap, but also it is a weapon held in plain sight that is kinda aggressive. Know that sometimes I carry up to three rigged Leicas (mostly carry two all day), but it appears I can always fight if I have too.
I hope I'm stating the obvious: Wear shoes that you can either run in or fight in. I like either sneakers or construction boots, be prepared for both.
Cal