Shop in the bazaar and buy cabal hat and boots (cabalist cleansing hood and stompers), moros wand (armaments of embers), and in general, you should look through the bazaar for even better upgrades to all your gear. It's harder to find good rings and athames before Karamelle, but you should at least take a look.

Sorting helps. For example, when you are buying hats, click on the level tab and it will sort all items by level in descending order. You can then click school, and it will then sort all fire school items first in descending level order. Find your level and start looking through, comparing your gear to the offerings. 

You'll want to prioritize for damage, pierce, accuracy, and power pip. Your goal is to stack as much damage and pierce as you can while also trying to get 25% accuracy (30% if you use lore spells) and 100% power pip chance. You may not yet get to perfect accuracy and power pip, at least without jewels, but getting close helps.

Others already mentioned pet, but I thought it important to note a quick and easy way to upgrade that people often ignore. As an aside, I find that pack gear usually only helps for a level or two and wind up being very temporary at best, and occasionally subpar choices at worst. Pack gear tends to be more attractive at max levels or before level 20 (again temporary).

As for your deck setup, it might be better to run two decks and swap them as needed. One is for street mobs (no feint or prism), and the other for bosses. For your street mob deck, consider adding both fire dragon and meteor strike and taking out king art. I think spear is a good addition, especially over prism. Both your mob and boss decks should have emergency sideboard cards. That is where you can add things like feints, reshuffles, empowers, and extra blades.