Color

Here's a small simple tip. Next time while you are at your local wine shop, check a wine's color by holding the bottle to a light and turn upside down. Check for color at the bottle neck. The glass is thinner at the neck and gives you a more accurate result... A darker wine has more tannins meaning it was left in contact longer with grape skins while fermenting. This is the cotton mouth feel a wine leaves you in the finish. Some wines are more tannic some less. Depends on your palate. It's a personal taste!