Ninkey | 🇰🇷 ✈️@ninkeygwen
I used to make this same mistake until I started getting punished for it by really good resource gathering junglers in high elo.
You have to understand that objectives and ganks don't matter, every good jungler in high elo ONLY PLAY FOR THEMSELVES. The play you made not only desequenced your camp spawns but you also gave rengar a free camp and a free kill on MF (if he is playing correctly) in exchange for one dragon and grubs which is useless.
Now imagine this is NattyNatt on rengar, that lead you gave him just lost you the game since he will be able to snowball to the point where he can get strong enough to prevent you from doing objectives for the rest of the game.
If you are ahead its fine to clear your weakside camps and then look to invade/dive when you have good setup and vision but full clearing is always the most optimal way to get resources.
You should always be clearing your camps before making plays, especially for lower elo players, the only time it is acceptable to sacrifice camps to make plays is when either:
1. You know your camps are completely safe AND the play you are going for has a greater return on investment
2. You are so far behind that you can't defend your camps and a champion or objective bounty is worth dropping camps for.
In this case you just have a poor concept of your return on investment, you should only be doing dragons when it won't ruin your tempo and lose camps. You should focus on matching rengar and denying him resources/plays instead of skipping camps and doing useless objectives.
Also you said to do this after having one item but most champions will start clearing so fast at this point you might as well just clear first and you will have a full minute or two of downtime to do whatever.
