There's a New Yorker article about how Facebook could be making us unhappy (or just slightly diminishing our quality of life). But the quality of your Facebook experience really comes down to the way you use it. And on that point, I have some tips.
I've found that hardened spittle on my laptop screen, from years of food detritus, has really improved Facebook for me. When I compare myself to the pictures of my peers and acquaintances with their beautiful smiles and trim bodies, surrounded by friends and sunsets, I can think - why is he so dirty, just smudge-smear all over his face? Doesn't she do laundry? Dirt spots all over that stylish outfit which includes boots. These people might have their fancy vacations and cameras and jackets, but at least I've kept an eye on my hygiene. (Says the woman recommending stain build-up on the screens of your electronics. At least I'm happy, OK!)
That's actually my only tip other than having enough self-control to stay off social media.
Oh, one more: if you want to feel more sympathetic towards someone, I would suggest looking at the photos that the person's taken/uploaded instead of just the one she's tagged in. It's helpful to get a small glimpse into how a person sees the world instead of just what she looks like.
That's my advice on passive viewing! Go forth and whittle your time away more expertly.