- Do not take a picture of a friend's ultrasound with your phone to upload on facebook. Don't act all surprised if she yells at you. 'Oh, I didn't realize you didn't tell everyone yet' is not an acceptable excuse. If it's not your news to share, then stay out of it!
- Oh, and bonus points for people who post every single ultrasound when they know there are friends out there trying to have kids, then act all surprised when said friends remove them from the feed list.
- Do not post pictures of teddy bears being hanged. I will defriend you.
These are excellent points but I wanted to comment on your second point.
On the flip side - If you're trying very hard to have kids, it is
not going to be cathartic or therapeutic to post (daily) updates spewing, at best, snark, or at worst, vitriol directed at parents that jokingly complain about some parenting annoyance.
Insert whatever struggle you're having...but spewing at those who do not have that struggle and are making minor complaints or jokes is not helpful and may get you blocked or unfriended.