Tips for jungle?

vision and map awareness. Simple as. For exxample you see a gank down bot and you can't respond with a counter gank, you can pressure another lane, invade their jungle and steal camps or pressure other objectives. Same for if you have vision in their jungle too, and you know where they are. jungle is all about map pressure and control.
Don't be afraid to tax cs from lanes either, and make sure to hold lanes and push them in if your laners are backed and not trying to freeze it - as this denies enemies cs.
When you invade be sure to leave a single small creature left as that makes the respawn timer wait until they kill it, starving their jungler even more.
As game progresses into late game make sure to rotate and always have every lane pushing outwards with your team.
If you're alone and theyre rushing mid, go behind them and kill the minions behind them. This should cut off their push unless they have a fed tank to tank the towers.
can give plenty more tips if needed but I think those are good for now
Oh and always push your advantage. Dragons, towers, taking enemy jungle cs or getting vision every chance you can get. Starve the enemy team of whatever you can and apply pressure everywhere. Also when going for flash smites and you have vision, press smite on the objective before you flash over, as this puts it into a buffer ready for you to be in range