Simple drawing postcard

Step one:

First draw a rectangle.

The second step:

Then draw a vertical line inside and a few small squares on the left.

The third step:

Then draw a larger square on the right side and draw a few horizontal lines below.

Step 4:

Draw a square later.

Step 5:

Draw a triangle on the outside and also on the inside.

Step 6:

Then add two slashes to form an envelope.

Step 7:

Finally, apply a nice color and the postcard is ready.