Consumables in Total War: Arena are extremely varied and will give you that extra edge in a battle.
You can equip better armour for your weaker units, extra firepower for your ongangers or sharper sticks for your spearmen. It is good to have a good look round before you buy as you could use them points elsewhere.
For such a straightforward game, Total War: Arena hides how to buy consumables extremely well. Here is a quick step by step guide to how you can buy those little advantages.
Buying consumables in Total War: Arena
Consumables are actually attached to units, so the first thing you need to do is select the chosen unit that you think needs that extra bit of help.
Once it is selected you will see a little plus appear in the bottom right of the buffs and abilities part of the UI. This plus allows you to buy consumables.
Once you have pressed this button, you will be taken to a little menu explaining the consumables that are available to that unit in in Total War: Arena. Simply buy the consumable you'd like, and you're all done. Simple as that!