I use FB to keep in touch with family overseas. As my brother always says though, we need to keep in mind that with Facebook, we are the "product" being marketed! So, yes, keep your privacy settings locked down, and above all, hide your friends list, and never use FB to sign in to anything.
I'm actually trying to cut way back on my online time generally. Several friends are too, and a few have now deleted the FB app from their phones, and only use it when on laptop/tablet. One friend, a young mum, said she stayed off FB for a whole week, and said she was mortified when her husband remarked "Have you been Spring cleaning or decluttering or something? The house is so spotless!" It's just amazing how much time it eats up! I've taken up knitting again after many (many!) years, and am really enjoying it! I don't have tv, so it's nice to sit and knit in the evenings.