My goal is to get all the Skyrim achievements with a single character. I got many of them already by simply playing along and completing certain quest lines.
I discovered today that it is possible to take some perfectly normal actions that will stop you from completing an achievement. In my case it is missing a daedric artifact that cannot be recovered (although there might be a workaround as long as only one is lost - see answers in the linked question).
Now I want to know if there are other "fragile" achievements like that. I am not talking about blindly killing important NPCs or other obvious stupid actions. I am interested in quest items that are easily missed or decisions you can make that will mess up an achievement. I read about all the possible troubles with Oblivion Walker, please focus on the other achievements instead. Where can I easily go wrong so that I have to play the game again from the start with a new character or load an old savegame before my blunder?