1. Preparation tools: paper, pencil, eraser, pencil sharpener.

2. Determine the shape of the banana: First, draw the outline of the banana with smooth lines. Bananas are shaped like an ellipse, with one end thinner and the other thicker.

3. Draw a banana pole: Draw a short straight line as a banana pole at the top of the banana outline.

4. Refine the texture of banana peel: inside the banana outline, outline the texture of banana peel with thin lines, which can be combined with curves or straight lines.

5. Add light and shadow: Use an eraser to make a part of the area appear bright. On the banana stalk and banana peel, gently smear it with a pencil to make it show a gradual effect. In the depression of banana peel texture, the shadow is emphasized to enhance the three-dimensional sense.

6. Draw the pulp of banana: Draw the pulp part with shallow lines inside the outline of banana. The flesh lines can be slightly fuller to reflect the texture of bananas.

7. Refine the banana tip: Draw some tiny curves on the banana tip to make it more realistic.

8. Add a projection: Under the banana, use the eraser to create an area as a projection. On the projection, use a pencil to draw a gradient effect to reflect the change of light and shadow.

9. retouch the details: finally, use an eraser to remove redundant lines to make the picture cleaner. Gently add shadows where necessary to enhance the three-dimensional effect.

Some applications of sketch;

1. Painting: Sketch is the basis of painting. By practicing sketching, artists can cultivate observation, line control and spatial perception. In the process of painting, sketch plays the role of outlining, expressing light and shadow, and constructing space.

2. Sculpture: In the process of creation, the sculptor usually draws a sketch of the work first to understand the structure and proportion of the work. Sketch can help sculptors better grasp the image, dynamics and expressions of characters.

3. Architectural design: In architectural design, sketch is an important expression technique, which can be used to express the appearance, structure and spatial relationship of buildings. Architects can better display design concepts and ideas through sketches.

4. Illustration and animation: Sketch is the basic drawing skill in illustration and animation. Through sketching, artists can create colorful characters, scenes and actions, adding color to their works.

5. Education and teaching: As a basic skill of painting, sketch plays an important role in art education. Learning sketch will help students master the basic principles and skills of painting and lay the foundation for future artistic creation.

6. Product design: In product design, sketch is a commonly used hand-drawn expression technique, which can be used to express design concepts and ideas. Sketch helps designers to better show the shape, color and function of products.

7. Handicrafts: Sketch can also be used to make handicrafts, such as paper cutting and paper carving. Artists show their individuality and creativity by sketching, designing and making exquisite handicrafts.