It’s time to channel your inner Clark.

Griswold, that is — the holiday-lighting-obsessed hero of National Lampoon’s “Vacation” movies.

Whether your preferred look is extreme or subdued in terms of color and wattage, a little planning and some inexpensive hardware can make your display more attractive and safer.

The smart time to install exterior holiday lights is now — before it gets any colder.

The first thing to do is take inventory of the electrical equipment: lights, extension cords, power stakes and timers. All those things must be rated for outdoor use, says Garry Walker, manager at Strasser Hardware in Kansas City, Kan.

In addition, Walker cautions, if you live in an older home, make sure the outlet you plug your lights into is grounded (most three-pronged outlets are). In newer homes, all outdoor outlets are grounded.

Also make sure the outdoor electrical box is watertight. Use duct tape to seal it, if necessary. Water getting into the box could trip the circuit breaker.

Next, untangle your existing light strings. Then plug them in to check for burned-out bulbs. With newer lights, a single burned-out bulb won’t affect the entire string.

Any cords with a break should be discarded, Walker says. It could be a fire hazard.

When it comes to mounting the lights, do not reach for the staple gun. “If you staple through the cord, you could blow a fuse and ruin your lights,” says Walker. Even worse, he says, “you’re damaging your home. You’re creating holes ants or other insects could start nests in.”

Inexpensive plastic hangers and hooks that fasten to gutters or shingles are the way to go, hardware and landscaping experts agree. You can find them at hobby, hardware and discount stores for as little as $2 for a pack of 50.

Some people leave the hooks in place year round, says James Spurgin, assistant manager of Westlake Ace in Kansas City.

Measure the areas you want to outline with lights, and buy enough strings to get the job done. Cheating, such as joining two female ends with a connector is a fire hazard and will short circuit, Spurgin says.

You shouldn’t run more than three or four light strings per outlet, Spurgin says. You can buy outdoor-rated power stakes if you need additional outlets.

Make sure no lights are touching the house because they could start a fire, experts say.

If you have to use a ladder to mount your lights, practice good ladder safety, Walker cautions:

• Keep away from power lines.
• Make sure the ladder is in good shape.
• Make sure the feet are firmly planted on the ground and not sinking in loose bedding soil.

When it comes to trends, Spurgin says icicle mesh lights were a hit at his store last year. As for colors, last year blue was hot, he says; the year before it was red.