I can only mention what has been useful to me, hopefully it’ll be helpful to you too.
I’ve broken enough leads while trying to sharpen my pencils that a mechanical pencil
has become my default. You don’t have to worry about pencil sharpeners with those, just make sure you don’t drop them because the lead is extremely fragile and might snap in pieces too small to be used properly.
Then again, both the pencils and sharpeners I used were older than G4, and I think the pencils were cheap ones too. Maybe you’ll be luckier. And sharpeners (hopefully) allow you to sharpen much thinner than the mechanical lead (even if you use a knife on that one), although it doesn’t stay this sharp very long.
I also started drawing on the paper sheets I already had. Those were for printing, that meant a grammage of 60 g/m². That meant that once I was done drawing, erasing, re-drawing, re-erasing, etc, the paper was only a few nudges away from simply tearing through.
Switched to 90 g/m² a few months ago. I still work the same way but the paper’s intact. Full of eraser marks, but intact.
Finally, I use a big eraser when I need to erase big parts of the drawing, but a smaller, thinner ‘knife-shaped’ one for precision work. Which is what I need most of the time.
I’ve not used colored pencils yet, and I don’t ink my sketches because I can’t erase mistakes then. I do redraw over the lines over and over again though… which is why my previous sheets wore so thin to begin with even without erasing anything.
There’s also hardness ratings
to worry about… I just picked a box of HB leads when I started drawing and never paid any more attention. But I believe it influences how much the drawing stays on the paper, and so how easily it is to remove all traces from it with an eraser. Traces are less a problem if the results you upload go through digital cleaning or vectoring, obviously.
Hope it helps, I’ve never been a professional.