Mastering positive/negative relationships you can create wonderful and unique art and design pieces, look at the work of a very famous and talented designer Tang Yau Hoong

But before, you have to learn how to see these relationships, and practice some simple techniques

You can choose any object or better any part of it with an interesting shape: a plant, a flower or a leaf, beautiful jar or a vase, a face or the whole figure, a butterfly or an animal, a house, car, some technical shape… just look around. You can draw an object yourself or find a picture for the reference.

Let’s take a plant as an example. The shape of a plant's leaves and flowers is what makes each plant unique. Plants can have large, wide leaves, many small leaves or long slender leaves. Sometimes the leaves stick straight up and sometimes they gracefully fall away from the plant.
Here are: a plant, its outline, positive/negative composition

Phase 1, thumbnail sketches:
1. Create at least 4 different thumbnail sketches with pencil in your sketchbook: make a rectangle for each one, approximately 3-4 inches one side (it can be square, horizontal or vertical).
2. Draw an object (or its part) inside each rectangle so it completely fills the rectangle borders - touching at least three of the sides, but better all four. You can even extend the drawing behind the borders, and then erase the leftovers outside them.
3. In each rectangle, leave the object white and fill everything that is not the part of the object with pencil.
Thumbnail skethes:
Example 1
Example 2

Phase 2, bigger scale work:
Choose one best idea of your thumbnail sketches and make the enlarged final version on one sheet of Bristol paper:
1. Make one square or rectangle (approximately 5-6 inches side) in the middle of the page.
2. Make an accurate drawing of an object silhouette first with pencil, then accurately outline them with sharpie. Use a ruler if necessary.
3. Using the thumbnail as a reference, leave the shape white and fill the surrounding parts black with black ink or black paint with a thin brush. Make sure that the work is done neatly and professionally.
Look at the students’ examples (there are 6 examples, but you have to do only one work)

Note: beware of plagiarism
I am giving you plenty of examples for each project, and you can find even more on the internet. You should look at the examples, analyze them, digest, enjoy, be inspired, etc., but no way to copy them entirely.
Here is one example of plagiarism:

Here is not plagiarism, but rather homage:

Wikipedia definition: “Homage is a show or demonstration of respect or dedication to someone or something, sometimes by simple declaration but often by some more oblique reference, artistic or poetic. The term is often used in the arts for where one author or artist shows respect to another by allusion or imitation.”
Homage pronunciation