Continuity in writing is often one of my biggest headaches. Since I started writing - I've always been guilty of forgetful errors, usually it's in the form of clothing -
"Katie slipped her hand into trouser pocket to check her phone was still there.... Katie felt a chill on her legs, as her skirt caught the wind and flared up around her knees"- this is usually my worst, randomly changing clothing, or moving pockets. But recently I learned of a whole other issue, and only after writing it did I realise the silly mistake I'd made.
Doors open two ways, which may seem like a very obvious statement, and normally when writing or describing something you don't have to pay too much attention to what way the door opens. I'm also quite sure this is an area where I've made many, many errors in the past - but could bluff by it through saying the door opened both ways.
My current piece of writing involved barricading a door. The character opened the door towards her, went through it, then barricaded it on the other side by putting a chair under the handle. I merrily wrote on past this, but something else about the scene nagged me, so I put it down for awhile. Just as well, since a door barricaded in such a fashion would open easily, since it opened inwards, not outwards.
I've now fixed this by re-writing the scene in a way that I like, but still - there's a lesson to be learned. Even the most basic and seemingly silly details can be important, and it only took me 20 years of writing for pleasure to learn about doors, I dread to think what awaits me in future, continuity error education!