There’s no real way to farm specific resources outside of the enchantment boosts, but you can have one on each of your artifacts and they will add up - so 6 power enchants will give you 120% more power. Additionally, the Priest’s Relic consumable increases how much power you get from the next battle by another 100%.
You can compound this with the Nightwing Gargoyle creature available from Bynine, though each core costs 15 emblems, which at the beginning of the game is a hefty (though worthwhile) investment. It increases resource drops by 30% for each living creature on your team, for a total of another 180% for the whole team.
The fastest way to get more resources, with all that in account, is to go into the realms and search until you hit a buff shrine that gives you +100% resources from battle, and then spam minor sigils repeatedly. They’re not hard - equivalent to the monster-hunting Duty that has you fighting a single Nether - and Nethers drop significantly more resources than normal monsters.
If you put all that together you can get power five times as fast, not to mention how fast you’ll accumulate the other resources.