Welcome to part 3!
IMO, style is a fascinating topic. As I write, share, and critique more, it’s just as neat to watch other writers’ styles develop as it is to notice the subtle changes in my own.

I’d love to share with you what writing methods I’ve found myself leaning towards over the past year:

1. I often drop the word ‘that’.

I decided that I would go.

becomes:

I decided I would go.

But not always. I try to play a mix-up game when I write—I don’t always follow a rule. For variety’s sake.

2. I play a mix-up game. :)

I try not to let any of my writing tendencies set in stone, lest I not get better at the aspects of writing I sucketh at.

3. I italicize thoughts.

One thing I love to do in my stories is italicize the thoughts of the POV character during narration:

She watched in awe as the crowd parted for the soldiers. Someday I’ll enlist, too.

Mmm… so effective. So stream-lined. The reader gets lead straight into exactly what’s going on in the character’s head in real-time. No fumbling with quotes, tags, or extra commas.

When I employ this method, tagging the POV character’s thoughts isn’t something I do very often. But I’ll sometimes throw on a tag if it flows with the narration and sounds good to my inner-voice.

She thought, Someday I’ll enlist, too.

4. I tend to use lots of contractions. Especially in dialogue.

What will -> What’ll

That is not proper. -> That’s not proper.

This tendency of mine stems from being a fan of the dialogue and narration found in Sam Keith’s The Maxx.
Mine’s a mild variant, though (“What’re ya doin’?” is a good example of what can commonly be found in The Maxx‘s dialogue).
In my stories, poorer characters tend to use more contractions in their speech patterns than the wealthy.

5. When listing items, I add a comma before the last item in the list.

I went to the grocery store, stopped by your house, and went to the post office.

Ha! That example sounds so text-booky. :)
Some people prefer to not add that last comma before the word ‘and’, arguing the word itself serves to separate the final two items anyway.

At this point I’m not sure which way is better. I was taught early on in life to add the extra comma. And I guess it stuck with me.

6. I start sentences with conjunctions.

That night, I was too far away. But I swore I’d never let it happen again.

This is another one of those situations where teachers told us never to do something that is perfectly okay. I love this technique.
Oh, and I often play a mix-up game with this one. It could just as easily be:

I was too far away, but I swore I’d never let it happen again.

7. I try to use both long and short sentences.

(Not sure if this should be considered a good writing habit or part of my style…) Sometimes, writers can get carried away, chaining lots of clauses together. Or maybe they have a penchant for using overlong, complicated sentences. I try to keep that in mind so I can force myself to add the occasional short sentence—give readers some breathing room.

8. I avoid rhyming at all costs.

After crossing Abyssmal Gorge, he finally saw it: Iron Forge.

Granted that was a cheesy example. But even when the last sentence of a previous paragraph has a rhyming word—even when the words are near-rhymes—it can be jarring to the reader.

9. I avoid parenthesis in my stories.

(Yes, I use them a lot when I blog.) I rarely see them in a serious novels. But I do see them a lot in comedic novels. Maybe it’s because parenthesis insinuate you weren’t able to fit an idea into a sentence? Or for further clarification? Or maybe the writer forgot to mention something? It’s like saying, “Oh! As a side note… Giants are allergic to juju grass”. Correct me if I’m wrong (both on the use of parenthesis and on the effects of juju grass on giants).

10. Semicolons are rare, and hyphens are rarer.

IMO, the semicolon is one of the most mighty, under-used punctuation marks in existence. But be careful; overuse of it can come off as pretentious. In my casual writing, I’m all over the place with semi-colons and hyphens. In a serious piece, I try to come up with specific rules for when I can and cannot use semi-colons and hyphens and stick to them like burrs on velcro.
An example of where I might use a semicolon in a novel:

It was never sentiment; he could do without the bittersweet memories.

I don’t usually link semicolons into words like ‘therefore’.
I’m sure you know the difference—sometimes I catch myself swapping symbols, so be sure you’re not mixing up the semicolon and the colon.

That’s all I can think of right now, but there are so many different elements in styles that it’s hard to cover them all.

You might even have certain ascetic themes and subject-matter that link together every work you’ve ever written. I subscribe to a few author newsletters. Last year, one of those authors gleefully announced she discovered a common theme that linked together all of her previous works: wishing she could fly.