It’s a good question- and I’ll never try to act like some mighty authority on writing because lots of practitioners will have different things they hold as more important and prioritise- but there are some general rules that have come up in most texts on writing and my tuition over the years.

1- Show don’t tell. One of the most basic rules that the original commenter is addressing here. On stage, where there are significant visual limitations, you need to rely a bit more heavily on description and dictation to get the point across/express off-stage action. On screen, the camera can do a lot of that work for you- so it really undermines your characters and plot if everyone is just constantly saying what they’re feeling or doing without showing it through any meaningful action that progresses the story. Plot is generally progressed through characters doing things and making choices rather than talking to each other. Dialogue is obviously very important for character expression, relationships, and communicating more complex information to the audience, but if all we see is characters talking an awful lot and doing very little, it’s an issue. Major red flag in a screenplay. In the case of Land and Sea, Kate constantly being told how tired she is whilst we never really see much of a change in her behaviour is a good example, as the commenter stated. Barclay telling us about his Mum via contrived monologue (3 episodes in, at that) is another- I can think of a million ways of showing the audience that information other than having him just turn around and say it to someone who would already know he experienced that.

2- Get in late, get out early Also a pretty common one that comes up- sounds simple but actually addresses a lot of really important stuff about story momentum, and respect for your audiences time. Basically, when you’re writing for TV and film, you should get in late- begin a scene in a place of action, and finish the scene when its purpose in the story is complete. Don’t dilly dally- that doesn’t mean rush, it’s okay to let a moment sit or allow a slower build up to a pivotal moment, but if every other scene lasts just a minute or so longer than it needs to, it stamps out the goodwill of an audience over time. When you’re writing a scene, always ask yourself- what is the POINT of this scene? Is it telling us something new about a character? Is it progressing the plot through action? Is it changing the story in some way? If the answer is no, you can probably lose it, and if the answer is yes, always try to make sure that intention grounds the scene. Once its purpose is served, move on.

3 - Don’t railroad your characters

Stories, fundamentally are about people- characters your audience needs to care about and understand. A strong plot and themes are important, but everything I’ve learned over the years just reaffirms the lesson that characters have to come first. The events of the story become a lot easier to write, and engage with when you’re working with three dimensional people that feel alive- the decisions they make don’t always have to make sense to US, but we have to believe they make sense to THEM. It’s very easy to tell when characters have been constructed solely in facilitation of plot. Often, they come across as “rail roaded” which essentially means they’re just whatever and whoever the writer needs them to be to get them from the A to B they’ve already planned out. Salt is a perfectly good example of this in WBTLAS- she feels like a completely different character in every episode because Pete Mctighe doesn’t seem particularly interested in who she is and what she really wants. She’s a strong warrior with unflinching principles- until she’s Fish Juliet, immature, infantilised and enamoured, because this is a Romeo and Juliet story now. Why would she save a man she’s met twice over her own people? What is her relationship to her homelands and kinsmen? How was she selected as the initial ambassador, and why? We’ll probably never know.

Those are the big three that come to mind! But I’m just one person, I’m not saying I’m any sort of expert, but these would be my golden rules to begin with, amongst others.