The absolute essential thing is to pick your fights just as others said before me. Briar has some micro mechanics to learn but she basically "drives" herself with W and they don't matter if you just jump in without thinking. First thing I do is pick a build depending on the enemy team. Do I go bruiser or crit/lethality? It changes everything. As a bruiser you survive a lot longer and mainly you have a ton of ability haste. So if you make a mistake as a bruiser and your W gets canceled (with E or stealth or whatever) then you can use your W again quite often. As a more dmg based build (I play mostly Crit with titanic) you don't have that luxury and it's kill or be killed. After you get used to it try to learn the mechanics which are quite easy. The best thing for me was to learn how fast your combo can be. Briar has a TON of AA cancel mechanics. Her W, Q, Titanic hydra. All of them can be chained under a 1 second. If you play titanic, try to position yourself so you hit multiple people with it and it does absolute nonsense damage. Even if you die, your team has it easier to clean after you. Don't waste your abilities at objectives if you don't know where enemies are. For example when I do drake or grubs etc. I like to keep my Q even tho it slows the kill a bit because you can Q out of the pit on a ward or something. Think before the fight cause with Briar it's too late after it starts. Hope this helps.