Make a three-dimensional sketch of a piece of furniture or any other object, first of all creating a 3D block.
This should be used as a guideline.
A 3D sketch reproduces the width, height and length of an object.
The horizontal edges are represented at an angle of 30 degrees. The vertical ones, on the other hand, remain so.
Steps

Step 1. Purchase a block of graph paper
Or, on a white sheet of paper, make a grid of equivalent squares yourself.

Step 2. Count 10 squares starting from the left edge of the paper

Step 3. Draw a dot on the lower right corner of the square closest to the center of the paper

Step 4. Mark this point as # 1
Count the lines to locate the next point, or use a ruler to measure the distance.

Step 5. Count 12 lines to the right and, from there, 7 up from point # 1

Step 6. Mark this point and name it # 2

Step 7. Use the ruler to join points # 1 and # 2 with a smooth line
This is tilted 30 degrees.

Step 8. Go to step # 1
Count 7 lines on the left and 4 on the top.

Step 9. Mark this point and name it # 3

Step 10. Use the ruler to join points # 1 and # 3 with a smooth line
This forms a 30 degree angle to the left.

Step 11. Go to step # 1
Count 8 lines up from here.

Step 12. Mark this point and name it # 4

Step 13. Use the ruler to join points # 1 and # 4 with a smooth line
This is perfectly vertical.

Step 14. Go to step # 3
From here it counts 8 lines upwards.

Step 15. Mark this point and name it # 5

Step 16. Use the ruler to join points # 3 and # 5 with a smooth line
This is perfectly vertical, parallel to the one drawn to join points # 1 and # 4.

Step 17. Go to step # 2
From here it counts 8 lines upwards.

Step 18. Mark this point and name it # 6

Step 19. Use the ruler to join points # 2 and # 6 with a smooth line

Step 20. Go to # 1
From here it counts 5 lines to the right and then 19 lines upwards.

Step 21. Mark this point and name it # 7

Step 22. Use the ruler to join points # 4 and # 6 with a smooth line
This is parallel to the one that connects points # 1 and # 2.

Step 23. Use the ruler to join points # 4 and # 5 with a line
This is parallel to the one that connects points # 1 and # 3.

Step 24. Use the ruler to join points # 5 and # 7 with a line
This is parallel to the one that connects points # 4 and # 6.

Step 25. Use the ruler to join points # 6 and # 7 with a smooth line
The unmarked segments form a block, which will be the guiding pattern for designing the furniture.

Step 26. Make a sketch of a piece of furniture inside the block
Draw all the lines of the cabinet so that they are parallel to those of the block.