Are the proportions right? Nope, but I like to work directly in ink. I think a little wonkiness makes it fresh. (9 x 12 inch brush pen and watercolor sketch.)
I think using flat brushes helps take the fussiness away and also adds to the wonkiness.
Let go and let your sketches be a little wonky today.
And then don’t beat yourself up afterwards.
It’s a sketch, it was fun. Go read a book.