The principles of design serve as a guide lines for combining elements. Again, the way in which these principles are applied affects the expressive content, or the message of the work. Fashion Designers are taught Principles of designs in beginning of their student life, so in futures they may not consciously think of these principles as they work but if some thing is wrong with a design, they are able to analyze the problem in terms of proportions, balance, rhythm, emphasis and unity to create a harmonious design.
The principles are:
1. Balance
4143375717550 Balance refers to visual weight in design. A garment must be balanced to be visually pleasing. Balance is also the concept of visual equilibrium, and relates to our physical sense of balance. Balance can be achieved in one of two ways:  symmetrically   or  asymmetrically.

Symmetrical balance  can be described as having equal "weight" on equal sides of a centrally placed fulcrum. It is also known as  formal balance . In this case the design composition is same on both side of the garment, then the design is considered symmetrical or formally balanced, following the natural bisymmetry of the body.


Asymmetrical balance , also known called  informal balance . It involves placement of objects in a way that will allow objects of varying visual weight to balance one another around a fulcrum point. To achieve a more exciting, dramatic effect asymmetrical or informal balance can be used. A asymmetrical garment will make pattern layout more difficult as a result are expensive.

4124325-485775 2. Proportion
Proportion is simply the pleasing interrelationship of the sizes of all parts of the garments. Standards of proportion change with fashion cycles along with the evolution in silhouette and line. The length and size  of design features like pockets, trimmings, surface ornamentation or parts of garments within the silhouettes should compliment the whole.

-3810034925 3. Rhythm
Rhythem is a sense of movement and is necessary to create interest in a design and carry out the central theme. Rhythm can be achieved by   the repetition of lines, shapes and colour to get direction.

4391025200025 4. Emphasis
Emphasis or a centre of interest draws attention to the focal point of the garment. It marks the locations in a composition which most strongly draw the viewer's attention. A centre of interest should be related to the total structure of the garment. A focal point can be achieved by colour accents, significant shapes or details, lines coming together, groups of details or contrast. If fashion designer is working on particular client, and the client has some interesting features e.g. — very beautiful shoulders or neckline, then the designer could add some interesting features or emphasizing the garments that will enhance the clients best part of the body.
5. Unity
A successful design is achieved when all the elements and principles of design work together and Unity works here. Unity is the underlying principle that summarizes all of the principles and elements of design. It also the  coherence of the whole , the sense that all of the parts are working together to achieve a common result; a harmony of all the parts and at the end to form a successful design.