What’s the first thing people see when they walk up to your home? The front door, of course. It can make a big impression — good or bad.

A visitor rings your bell or knocks, and as they’re waiting, they examine that portal closely for a few seconds: the stain or paint, the handle and other hardware, windows, hinges, doorsill, frame. Is your door dramatic or utilitarian? Immaculately maintained or weather-beaten and dirty? That simple slab of wood (or fiberglass or steel) can convey a wealth of messages about you.

Exterior doors face a harsh environment. The big difference between high and low temperatures can cause wooden doors especially to expand and contract, making them difficult to open on hot days. But be careful not to sand the edges down too much — a snug-fitting outside door in summer will contract considerably when the weather’s colder, creating potential draft and rattling problems.

Scott Sidler of Austin Restorations, a home-restoration company in Orlando, Florida, recommends spot-checking your outside doors at least once a year for chalky and peeling paint or other signs of damage.

There are two ways to see if the stain on your door is getting old, according to doityourself.com:

“A raised wood grain with a dry, rough feel means the finish is beginning to fail and needs to be reapplied. Dark streaks in the wood under a clear finish or a light or whitish haze to the finish itself may mean moisture is getting into the door and the finish is failing.”

It’s time-consuming but not difficult to refinish your exterior wooden door. For best results, remove it from the frame by tapping out the hinge pins and placing it on two sawhorses.

Remove all hardware then strip all six sides of the door with a high-grade paint stripper or paint remover. (I get good results with Jasco Paint and Epoxy Remover.) Two applications may be necessary for seams. After wiping it thoroughly, sand the door gently in the direction of the grain with fine sandpaper (150-180). If the door surface is rough, perform your first sanding with medium sandpaper; 120 grain is ideal.

After sanding, clean the entire door using a cloth dampened with mineral spirits. After it’s dry, apply a coat of high-quality exterior primer, then a coat or two of exterior paint. Exterior acrylic paint with anti-mildew properties works best. Lighter colors absorb less of the sun’s energy than darker colors and should therefore be more durable.

Perhaps your front door is simply too weather-beaten to repair, or maybe you want to go with a new look.

It’s easy enough to go to Home Depot or another big-box home supply store and order a door, at least if you have a standard-size opening. But in most cities you’ll find a small yet thriving community of specialty retailers who sell and install high-quality doors.

The first decision to make concerns materials: steel, fiberglass or wood.

Steel doors are affordable, durable and strong. They can be ordered with windows, glass inserts and other details. Fiberglass has some of the more desirable qualities of wood, but its cost is usually lower and it has greater durability.

Wood doors can be mid-priced or expensive; the type of wood, number of windows and complexity of construction can increase the price dramatically. They also require regular maintenance.

Doors go through trend cycles, just like other elements of home design.

“Right now, Dutch doors are really popular, though they can be difficult to install,” said Malik Jaleel of Today’s Entry Doors in Orange County, California.

Door configurations depend on the size of the entry hall. Double doors create a feeling of grandness, but even a sidelight on each side of the door can achieve the same effect if you’re short on space.

Lastly, how do you want your visitors to announce themselves? A doorbell? A fancy knocker? An intercom system? Make sure there’s space for them, and get something as classy looking as your new door.