Before you do anything, look at the whiskey. You can learn a lot from its color. Generally speaking, the darker the whiskey, the older it is because whiskey gets its color from contact with the oak barrel during aging. The type of barrel matters as well. For example, a scotch whisky being aged in a bourbon barrel that has been used several times is not going to pick up as much color from the barrel. If that same whisky was put in a used sherry or port cask, it will pick up some of those colors in addition to the oak barrel.
You can smell more from your whiskey than you will ever be able to taste. Most master distillers and blenders work primarily by nosing, not tasting. So, always smell your whiskey before you taste it. Don't shove your nose into the glass or the alcohol will be too dominant. Gently raise the glass to your nose until you begin capturing the aroma. Think about what you smell. Closing your eyes can help you differentiate between aromas.
Make sure you coat your entire tongue and let it linger on the palate before swallowing. Does it taste the way it smells? Do the flavors evolve on the palate or stay the same? Does the whiskey feel thick or thin? What flavors do you taste? After you swallow, does the flavor linger or quickly fade away? Sometimes the alcohol is too intense to fully appreciate the whiskey. Add a couple drops of water at a time to the whiskey till you find your comfort zone. Not only does the water lower the proof of the whiskey, it can help open up the aromas of the whiskey.