Update: I switched from a 0.5mm mechanical pencil to a 2H clutch lead holder for my initial layout lines.

That's a solid tip. I've been down that road with smudged pencil lines ruining a clean sheet. The switch to a harder lead makes total sense. It's one of those small changes that saves a ton of frustration later. I stick with a non-photo blue pencil for my rough layouts. It scans out clean and keeps the sheet looking sharp. Finding the right tool for that first stage is a game changer.