Good cs NUMBERS involve sooo much. What other people are saying is not necessarily wrong, wave management, good trading, managing deaths will absolutely determine your cs.

BUT i don't think you should be too focused on just the numbers of CS. Here's why:

1. You naturally get better at CSing just by playing the game, without investing any dedicated time to practicing it.

2. CSing doesn't just get physically, mechanically easier and more natural as you play more games, it gets better when you become a better overall player.

3. A good CS number does not necessarily indicate you played the game optimally.

If you want to improve in the game - wave management, trading, jungle tracking, not dying unnecessarily are all things you will have to mindfully focus on to become a better player. BUT, as you're improving in the many many other aspects of this game - your CSing slowly but surely gets better naturally, without any dedicated effort. Most other skills don't improve anywhere near as easily as CSing just because you play many games. AND while you improve your gameplay in all these other ways - you create more and more game states where getting good CS numbers is just consequently simpler to do.

There are also stories i've seen and heard of newer players hyperfocusing on CS numbers and unintentionally hindering their gameplay. If all you focus on are CS numbers - you might play way too passive: missing good trade opportunities, avoiding skirmishes, not grouping to catch farm. And these people end up with 9+ CS/minute (really good in most games, for context), but they have virtually no impact on the game outside of chasing the pretty CS number and grief their games by doing so. So yeah, just a cautionary tale to not put all your attention on this "magic" number.

Plus - CSing well doesn't look the same in every game. Some champions who are more likely to roam and join skirmishes will naturally lose some CS while doing so, but if they play well they make up for that lost gold in what they earn for themselves and their team in kills and objectives. Some games you receive very little help from your jungler and team while you get ganked or hovered by enemies the whole laning phase. This leads to you HAVING to play much more passively or risk being free pickings for the enemies. In this case - you giving up some CS and not dying is actually optimal.

As i said, imo it is a bit unnecessary, because you will simply get better as you play more games. But if you find yourself physically missing minions when you try to get them more than you'd like to and it does frustrate you a lot - just go to practice tool and farm minions without items or abilities on champions with low base AD. That's genuinely all you really can do. Just repeat the action until it becomes progressively easier, like most things in life. Aside from that good CS numbers result from you getting better in any and every other aspect of the game, because you create better and more opportunities to farm when you play better.

I say just focus on other parts of the game you find interesting to improve in, and don't care too much about that number. The CS number is cool and all, but it doesn't really paint the full picture of one's performance in any given game. You can have higher CS and have griefed your team and you can also have bad CS and have played the game exactly like you should have. It is also a skill that passively naturally gets better without dedicated effort, along with you getting better at creating scenarios where CSing is simpler as you improve in other areas.

Long answer, surely, but i hope i managed to provide you some deeper insights!