How Do Independent Bands Fund Bigger Music Projects?

I have noticed that many independent metal bands are creating better productions, touring more often, and investing heavily in recordings and equipment. It makes me wonder how smaller bands usually manage the financial side of these projects without major label support. Do most artists rely on personal savings, crowdfunding, sponsors, or professional guidance? I recently came across the idea of Private Capital Advisory while reading about ways creative businesses find funding options, and I'm curious if anyone here has experience with similar approaches in the music scene.