the biggest turning point for me was not bothering with making a mesh a single piece. screw it, the table will have each leg be a cube, the rifle grip will be its own piece, the shoulders free-float and have pauldrons over them or something. output and practice skyrocketed
You could dedicate every hour of your waking life to 3D art and spend the rest of your working life squinting at photorealistic gun attachments with perfect topology.
I present an alternative: half-ass it, make what you need, learn as you go, and be Just Okay at it. That's fine.