I'm going to pivot my answer: it's not the best thing I've found on HN, it's how I use HN to find things.

- Ask questions about things you're unsure of, even if it's just TLAs.[1] I also like to ask for references, and those can occasionally be real gems.

- Respond to others. Especially, respond in a "yes, and..." rather than a "no, but ..." style, where that's possible.

- Avoid tendentious arguments. I'll point out corrections, but try to keep those short where possible.[2] Changing minds is ... difficult at best. Leaving clues for other readers may have value.

- Skip the main page and hit the lists: <https://news.ycombinator.com/lists>. "Best", "Invited", and "Pool" especially are worth exploring.

- If you find someone interesting, check to see what they've submitted. Often individual's submissions are interesting curations of their own, though often these fail to survive the HN queue.

- Use search. I rely on HN somewhat to search terms or individuals of interest, and to look for commentary on articles I turn up to see if there's any illuminating relevant discussion (especially older articles). This isn't always successful, but it's virtually always worth the effort, particularly using DuckDuckGo's !bang search capability: "!hn <search terms>". A blank search with a date range serves as a "best of day/week/month/year" feature (see comment below).

- Try to read the article first, or at least early in your perusal of the comments thread. Comments ... often ... deviate from and/or are only very vaguely grounded in the article itself.

- There are a lot of people shooting from the hip. There are also some absolute domain experts and Internet legends who drop by. It's quite an eclectic crowd, though the gems may be well hidden.

- You can read an individual's comments and posts from their profile. Reading the dang's (HN's moderator) comments is a good way to familiarise yourself with HN's culture and norms: <https://news.ycombinator.com/threads?id=dang> You can also email mods (hn@ycombinator.com) with questions or concerns about the site and/or your account and activity.

- Karma and votes count for far less than you'd think, though they tend to filter out obvious crud pretty well.

If you're interested in things I've found interesting on HN, I've favourited far too many submissions. There might be some gems (and embarrassments) amongst those: <https://news.ycombinator.com/favorites?id=dredmorbius>

I've also been looking at HN's historical front-page activity and have a sense of the topics which are most covered (based on classifying the submitted site). The top 20 (+ "UNCLASSIFIED") of those represent 97.6% of all front-page posts, and are:

Class Stories Votes (mean) Comments (mean)
UNCLASSIFIED: 63543 12353558 194.41 5492437 86.44
blog: 22711 4023053 177.14 1882979 82.91
general news: 15144 2927086 193.28 1904722 125.77
tech news: 13883 2254571 162.40 1261577 90.87
programming: 12856 2814625 218.93 957105 74.45
corporate comm.: 8655 2092856 241.81 981934 113.45
academic / science: 8463 1451758 171.54 609273 71.99
n/a: 7294 1143594 156.79 848020 116.26
business news: 5327 934668 175.46 695350 130.53
general interest: 3846 683416 177.70 395366 102.80
social media: 2151 707530 328.93 372925 173.37
software: 2085 466503 223.74 188013 90.17
technology: 1613 292982 181.64 133882 83.00
video: 1463 249221 170.35 94161 64.36
general info (wiki): 1144 180039 157.38 72192 63.10
government: 1009 274549 272.10 162660 161.21
misc documents: 724 127352 175.90 54601 75.42
law: 720 183559 254.94 66061 91.75
tech discussion: 702 128731 183.38 52805 75.22
science news: 625 94731 151.57 48919 78.27
general discussion: 609 180094 295.72 82509 135.48
Other: 4315
Total: 178882

(Data through 21-6-2023, code is sort of an evolving situation, and the tallies above fix some errors in other recent similar posts, though overall magnitude shifts are fairly small.)

Edits: A few late tweaks and additions partially based on my follow-up comment below.

________________________________

Notes:

1. Three letter acronyms. See also ETLAs (extended TLAs) and DETLAs (double-extended ...).

2. There are ... many ... exceptions to this. It's a goal and aspiration, not an accomplishment.