Im not the DIY electrician... been a state licenced journeyman for about 20 years. Work in an industrial setting currently, spent 15+ years in the residential/ light commercial field. I like to think I understand electricity better than the average DIY, but humble enough to know I'll always have more to learn.
My go-to is what I call an 'idiot stick', a volt sensening pen, that requires no contact with live conductors, but glows red if any AC voltage over 90 volts is present, and reads if a,wire is live thru the insulation coating. It is one step of verifying that a wire is dead, hence idiot stick. You're an idiot if you don't use it, but you're an idiot if you trust it without verification.
At work, we have a very strict 'hot work' policy, anything over 50v and I gear up in an 8cal arc flash suit, complete with face shield and rubber voltage rated gloves and tools. A real PITA, after years of working things live with nothing to save me but safe habits and luck, but they pay me by the hour, and pay me well... I'll put on that suit and fill out the hot work permit as required, and go home alive.