Zelda: Breath Of The Wild - 20 Things You Didn't Know You Could Do
9. Upgrade Your Armour
I didn't find this until a good 40+ hours in, but there are a number of places where you can find 'Fountain Fairies', who after paying them increasing amounts of Rupees will buff your armour by a couple of points per piece.
Bonus fact: You can wear armour in 'sets' (head, torso and legs) to get specific buffs, too.
Anyway, as for the Fairies, there's a full list of specific locations over here, but sufficed to say, once the story heads to Kakariko Village, visit the Shrine, take the right-most path then a left at the fork road and you'll find a strange-looking, rather enclosed plant.
Interact with it and the Fairy will emerge. Straight-up, you'll want these armour buffs - Breath of the Wild can go from 'carefree adventure' to 'brutal one-shot kill' in a heartbeat.