To supplement Adamant's answer, from Harry Potter: From Page to Screen by Bob McCabe, I have pictures of some of the characters' wands. It's interesting to see how much the wands' designs do fit their owners' personalities!
Yes, Slughorn's wand has antennae at the end of the wand, and Narcissa Malfoy's wand was designed to match her husband Lucius Malfoy's. Also as noted above, Hattie Storey is the art designer and Adam Brockbank is concept designer on the Harry Potter films.
"I think it must be a wonderful moment for the actors," says Brockbank, "when they put on their costumes for the first time and wield their wands, which are the sheerest expression of their characters."
Adam Brockbank - Concept Designer, Harry Potter films - from Harry Potter: From Page to Screen by Bob McCabe - Page 481 - The Wands
To expand slightly on what Adamant wrote:
Snape's wand is slim and spare, with no embellishments, while Bellatrix Lestrange's has a curve in it, almost like the talon of a bird of prey. Embedded in Dolores Umbridge's wand is a jewel -- pink, of course. "On the handle end of Horace Slughorn's wand," art director Hattie Storey notes, "are two little antennae, like a slug or snail." Brockbank designed Narcissa Malfoy's wand to echo her husband, Lucius Malfoy's. "I took the same black wood the was used for Lucius's cane," he says, "and embedded silver studs, essentially doing a more feminine version of his wand."
Hattie Storey, Art Director, and Adam Brockbank - Harry Potter films - from Harry Potter: From Page to Screen by Bob McCabe - Page 481 - The Wands
Bellatrix Lestrange's wand (Helena Bonham Carter)
Bellatrix Lestrange's wand in action!
Horace Slughorn's wand - concept art
Narcissa Malfoy's wand - concept art
Narcissa Malfoy's wand
Lord Voldemort's wand - Note the hook at the handle end of the wand -- it's a perfect place to rest a finger. Or so says the Dark Lord.
The Death Eaters' wands
More Death Eaters' wands
From left to right: 1) The Carrow twins' wand design (a twin design twisting down the handle) 2) a Beauxbatons student's wand (Ornate and fancy, like Beauxbatons' students) 3) Igor Karkaroff's wand (A bit confused looking!) 4) Dolores Umbridge's wand (With pink jewel, deceptively soft - it's in the middle of the wand. It's a bit hard to discern).
I went onto Google to try and find other wands examples; unfortunately, mostly what I found was the "official" replicas from Warner Brothers, and right off the bat I noticed some of the replica wands didn't match wands that are described on both Pottermore and in Bob McCabe's book. In some instances, the actors were photographs with different wands for different publicity stills. For example, Luna Lovegood's wand(s) (Evanna Lynch):
Luna Lovegood performing the Patronus Charm -- note that her wand is made from a darker-colored wood.
Luna Lovegood seemingly with a new wand made of blonde wood; runes of some kind can be seen carved into Luna's wand.
Close up of Luna's wand, with runes
Finally, for fun, a pic of a wand holster. Concept art by Rob Bliss. According to Harry Potter: From Page to Screen, the prop makers designed a series of wand holsters for the Death Eaters that would attach around their waists for easy access:
Wand holster for a Death Eater