Decide how many elements you want to incorporate in the emblem. If the emblem is meant to represent an entire family or other large group, several elements may be necessary. If the emblem is supposed to represent one individual or a small group, a single image may be preferred as being more directly communicative.
Select the elements to incorporate into the emblem. Elements are usually selected for their symbolic nature. For instance lions may be used as symbolic of power, the color green as symbolic of land, an anchor as symbolic of a sea-faring business.
Make a rendering of the emblem. The old fashioned way is to use pen and ink, but you may prefer to use software such as Adobe illustrator. Develop several versions so that the superior rendering can be used. Once an acceptable rendering of the emblem has been developed, contact a printer to have your emblem printed on stationery, clothing and other items as desired.