1. Canvas preparation: Select a suitable canvas, such as A4 paper or No.8 sketch paper. Put the canvas on the drawing board or desktop for easy use.

2. Color selection: consider using red, yellow, blue, green and other colors. Red and yellow can be used to depict national flags and fireworks, while blue and green can be used to depict natural landscapes such as grasslands and trees.

3. Draw the national flag: in the center of the canvas, draw a big rectangle, which is the national flag. Draw a small rectangle above the rectangle to represent the five-pointed star. Fill them with red and yellow.

4. Draw architecture: Draw some simple buildings in the lower right corner of the canvas. Colors such as black, blue and brown can be used to describe the outline and windows of buildings.

5. Draw fireworks: Draw some simple fireworks on the top left of the canvas. You can use red, yellow, blue and green to describe the color and halo of fireworks.

6. Draw people: Draw some simple people in the center of the canvas. Colors such as black, blue and brown can be used to describe people's contours and clothes.

7. Draw trees and grass: In the lower right corner of the canvas, draw some trees and grass. You can use green to describe the colors of trees and grasslands.

8. Draw the sky: Draw a beautiful sky in the upper part of the canvas. You can use blue and white to describe the color of the sky, and you can also add some colored clouds to increase the visual effect.

9. Detail processing: Detail processing of the whole picture, such as increasing light and shadow effects and enhancing color contrast. You can use white and light colors to adjust details, such as shadows and highlights.

Students draw pictures of National Day for the following purposes:

1. Enhance the understanding of the country and nation: Let students deeply understand and feel the significance and importance of National Day through painting. They can express their love for the motherland and celebrate the National Day by painting national flags, buildings, fireworks and other elements.

2. Cultivate patriotic feelings: For students, painting can let them express their love for the country and respect for the motherland. This will help to cultivate their patriotic feelings and enhance their national pride.

3. Improve artistic aesthetic ability: Painting is an art form. By letting students draw pictures of the National Day, they can exercise their painting skills and artistic aesthetic ability. They can create their own works of art through observation and imitation.

4. Cultivate creativity and imagination: Drawing pictures of National Day can provide students with unlimited imagination, and they can express the atmosphere and celebrations of National Day through their own imagination. This will help to cultivate students' creativity and imagination.

5. Enhance communication and expression skills: Through painting, students can express their understanding and feelings about the National Day more clearly. They can draw their own national day atmosphere and scenes and share their thoughts and feelings with others.

6. Promote teamwork: If teachers organize students to draw collectively, it will provide them with an opportunity for teamwork. Students can communicate and cooperate with each other in the process of painting, and jointly complete a work, thus enhancing friendship and understanding.