>>7648677
When I do a light undersketch I hold my pencil all the way at the back and very loosely. I don't follow the reference 1:1 as I think that makes the outcome too stiff so I try to be as loose and gestural with my lines as I can. I'll roughly sketch out the forms that I see and make adjustments to the shape/angle as I go while keeping the lines very light. In the case of the top right one, I erased the undersketch lightly and tried to make dark but still loose lines while following the undersketch as a guide (I don't trace the undersketch since it makes the outcome stiffer). I grip my pencil firmer for this too. If you can get it in one smooth line that's the ideal imho, but I feel that I wasn't confident enough to do that so my lines for the chin are kind of weak and scratchy.