Whether drawing line drawing Lohan or Guanyin. Buddha for good, how to practice the five senses to draw better?

Namo Amitabha Buddha

You should learn the fundamentals of painting, and when you have practiced painting the other ones and have a certain amount of merit, then you can paint the Buddhas and Bodhisattvas. Do you feel respectful practicing with buddhas and bodhisattvas without any merit at all?

Your painted statue of Buddha and Bodhisattva is a statue of Buddha, and should be properly enshrined or preserved.