I'm not saying I'm some genius songwriter or metal producer but here's a few under discussed topics that I wish someone competent told me a long time ago
If your takes aren't convincing immediately then your song will suffer and can't be salvaged, unfortunately. This is super obvious with vox but really applies to every instrument. It's fucking metal. You need to be energized during recording or else you can't possibly expect the product to sound convincing to the listener. You could try a number of things. Listen to your favorite album before the recording, run around the block 2 or 3 times, watch your favorite sports team championship highlights, smoke a small amount of weed, etc
Energy translates more so than the perfect "____ tone." Fuck chasing the perfect guitar, bass, snare, kick tone. I've mixed bands recording into the shittiest setup with Energy and it sounded better than some pristine boring stuff. Once again. It's metal. Have some attitude
Notice how all of your favorite albums most likely have appropriate sonic contrasts? If the vocals are extreme then the music matches that, right? If the vox are a little more subdued try and make the music around that feel closer to the vocal energy. Havig too much ofba mismatch with this feels disconnected and gives the listener a reason to turn it off. You can still be punchy and heavy without maxing out everything. If you're mixing a band who has more laid back vox try this.
Transition automation - Holy fuck I swear to God nobody talked about this for years. Give the listeners no reason to turn off the song. Make the transitions built energy and release. This is done usually through dynamics, automation, random sampling with fx automated, etc. You need it to feel like the song has motion instead of a flat and boring movement between the verse/chorus.
Change the second verse to something different, instrumentally. We as a society have shorter attention spans. Once again don't let the listener have a reason to turn it off. If you just repeat the first verse then we feel like we aren't moving forward with the song. It rejuvenates the song to have more energy in the second verse. This is my personal fav tidbit that helped me