Note color. Most crests have a solid background color or "field," which represents a desirable characteristic. Crests may be divided into sections with each section having a different color background.
Some of the more common colors used and their meanings, according to the American College of Heraldry, are as follows: Blue signifies truth and loyalty; black is for constancy or mourning and grief. Gold means generosity and silver and white both represent peace and sincerity. Ambition is orange, while hope and joy are represented by green. Red symbolizes strength, as in warriors and martyrs. Purple, as tradition suggests, is for royalty.
Lines dividing the coat of arms into sections may also have meaning. A wavy line, for instance, would represent sea or water. The heraldic dictionary online at the University of Notre Dame has graphic representations of these lines and their names.
An "embattled" line looks like the top of a castle wall and represents a fortress; a "nebuly" line has the appearance of one side of a jigsaw puzzle piece and symbolizes air or clouds. Other lines can represent earth, fire and overcoming difficulties or challenges.
Look at the picture. On a coat of this is called the emblazon. One or more separate figures, or "charges," may make up the emblazon. The possibilities are nearly endless, but one major category of charges features animals.
For instance, boars symbolize bravery and eagles mean nobility. Geese represent resourcefulness and bees mean industry. A lion symbolizes courage and snakes are for wisdom, while a pig represents fertility. Many other animals are seen on coats of arms, including dogs, deer, various insects and birds, mice and squirrels. Mythical animals are also common, from dragons to griffins, hydra and unicorns.
Look for images of shapes, symbols and plants as these also have meaning. An arrow would signify readiness for battle; a lamp, light or spirituality. Crosses were frequently represented; in the Middle Ages, this meant a soldier who fought in the Crusades. A crown symbolizes royalty, and olive branches traditionally mean peace. Many symbols have less obvious meanings: grapes for felicity; harps for contemplation; a mermaid for eloquence.
Look up any symbols, colors and pictures with unclear meanings in a heraldic dictionary. There are many available online as well as in printed publications.