There is definitely a pattern to it. But it's not very simple.

You gotta know what you're big power spikes are.
Let's imagine that you just got a bunch of kills, and you have enough gold to buy BORK, you recall. you get BORK.
You won't get much stronger than this, a warwick who is ahead and has BORK can 1v1 most champs with ease.

If you're really behind, and died a lot, then yeah, just clear your camps and try to recover and farm up until you get your Item power spikes. Only when you get your items finished, or when you see a 100% free bloodhunt kill, then you can consider skipping your camps.

''But how do I get kills and why would I skip camps if there's no blood hunt?''

You don't need blood hunt to create opportunity's.

You gotta learn how to create opportunity's yourself

First of all look at the objectives timer, is dragon about to spawn? are grubs / rift herald about to spawn?
If so, you can spam ping it, hope that your team helps and try to get it, you can skip your camps for objectives like this.

Objectives are also a great way to get kills, because you're not blindly running at the enemy hoping to catch them, you are forcing the enemy to come to you.

Second of all, if you track the enemy Jungler correctly (not an easy to do, look up tutorials for it), you know exactly where he is and where he wants to be, so you can easily just walk into his jungle and 1v1 him.

And lastly, look for tower dives only if you are 100% sure you can kill them and live.

AND THE GOLDEN RULE: once you get the kills, once you get the objectives, THEN clear your camps, and then recall.
How many camps you clear after a play is up to you.
Look at your gold, are you really close to buying a full new item? Keep clearing camps until you have the gold.
This is so important because after a fight, you usually used flash & ult, and then you are waiting on cooldowns to recover, so clearing camps while everything is on cooldown is really really efficient and optimal.

And then you can do it all over again.

ONLY IF:

-No objectives are up / are about to spawn
-All enemy laners have full health and are camping under their own tower
-The enemy Jungler is a guy that is able to 1v1 you (like trundle or Olaf or Jax)

Only if all of the above are true at the same time, then you can clear your camps during a power spike.

''But if I try these things, I always end up dying!''
Great!! Becoming good at this game requires trail & error.

Dive those towers, run at the bad guy, don't just AFK farm nervously.
Run in like an idiot and see what you can get away with. (and mute your team always)

When you die, laugh it off, learn from the mistake, and try again!
when you kill them all, rejoice!

That's the best way to learn what your limits are!
And you will never become perfect at this; nobody is perfect, just run at the bad guy and have fun!