One of the more pesky problems in the game is that the shortcut for item usage is assigned to the left shoulder button, while activating the rage meter uses both shoulder buttons. (glitchcat.com)
Since you don't have a lot of money to burn, the other option is sparse item usage. (mammothgamers.com)
Besides keeping the gameplay from getting stale, these additions are the perfect way to practice item usage. (goombastomp.com)