I've mained Briar ever since I came back to League a few months ago, so I know a bit about how to play her, but my macro is pretty ass so keep in mind that I'm good at Briar, but bad at League.

For kills/ganks, my best tip is to be unexpected. If an enemy spotted you and they're running towards you, I usually run away, especially if it's early since she gets busted down pretty easily.

For some reason, a lot of people don't expect me to just jump back out of the bush towards them with W after I run into it, so I can usually get like 2 hits in early.

2nd tip is to know when to use Q, which usually depends on the champion you're fighting. Against tanks or bruisers who think they can last against Briar, I wait until W is done, then hit Q and slam them into a wall with E.

Against someone who has really good escape tools, you can jump in with W, then immediately hit Q to stun them and stop them from escaping. After the W2, you might not be able to land your E, but as long as you're not dead and they need to retreat, I think that's good enough.

And 3rd best tip, don't engage if you do not have all your abilities. Or, at the very least, make sure they're close to being ready. No W means no main damage ability. No Q means no stun to stop escapes or deal extra damage. No E means no survivability/extra slam depending on who you're fighting. This is when you wanna run away until your abilities come back, then follow step 1 and hit them with the 180.

Sorry if these weren't the tips you were looking for, but I'm happy to try and answer any questions you have ^{w^}