Excelente trabajo amigo, la práctica de los bocetos es muy útil para hacer dibujos pequeños y practicar proporciones, aunque he visto gente con talento impresionante que usan estas técnicas para hacer dibujos más grandes.
Excellent work my friend, the practice of sketching is very useful for making small drawings and practicing proportions, although I have seen people with impressive talent using these techniques to make larger drawings.
Yes, it is a very basic concept, and I have also seen how even after a long career drawing they still use it, I think that as long as they feel comfortable drawing. I apply it many times