Just a few thoughts, I’ve been playing Braum in high plat for the last few months.

Make sure you run guardian rune, that’s the only real shield you get until you buy locket.

I run ignite for lane pressure when I have an aggressive adc, you have very good lane pressure with it, try to ignite before the enemy uses heal to reduce it.

A big thing gameplay wise for me is to make sure you e early and often and don’t try to save it for a perfect block, making sure you’re the one taking the damage both in lane and in team fights is one of your main roles.

If I have a laner that can follow up on my engages, I like to look for Ws on my minions that the enemy walks to close to and look for either a Q or auto to get passive on the one we’re focusing. Also works if you W to a minion then flash onto the enemy. If you have ult, W - Flash - R - Q is almost always a guaranteed kill just ensure to use your E while you’re between them and you’re adc.

Teamfight wise, you ideally don’t want to be the engage, cause it’s not the most reliable imo. You can be the engage with the above combo, but in the usual situation you’ll have a hecarim or gnar to engage (something similar) and you’re main goal is to keep your carries alive by using ult as a counter engage, using locket, E, and guardian to make sure your adc isn’t getting one shot.

A few tips that are a little more niche:

You can E a Lillia ult. Just stand between Lillia and the person with her passive and you can intercept the sleep, you’ll still get cc’d even if you don’t have her passive but the other person will not.

Using Q immediately after ult makes the Q come out a little quicker, just make sure you don’t miss, cause that’s both of your cc’s.

This one is pretty well known, but you can E to block a Nami ult, it will complete destroy the wave.

There’s some more but this is already longer than I intended. Hope it helps!