Provided by TotalBeauty.com

Celebrities have some of the best skin gurus in the country at their disposal, and plenty of cash to splurge on skin-perfecting treatments. But why then do some of them have less than perfect skin? Could it be the late-night partying? Too much fun in the sun? Read on to find out -- you may just learn a thing or two about how to take better care of your own skin.

*The doctors quoted in this piece have not treated these celebrities. Their observations were based solely off of these images.

Best: Halle Berry
Berry's nearly perfect complexion is envy-worthy. David Bank, M.D., founder and director of The Center for Dermatology, Cosmetic and Laser Surgery credits Berry's flawless skin to being careful in the sun, a great at-home maintenance routine and possibly Botox (average cost of $350 per area) and Thermage treatments (which firm and tone the skin and cost, on average, $1,000-5,000).

Still trying to find the right routine for your skin type? Take this quiz to find the best products for you.

Worst: Lindsay Lohan
Lohan's uneven pigment and dull texture leave much to be desired. Bank contributes the uneven pigmentation to time spent in the sun and "stress, smoking, lack of sleep and dehydration," he says. Lindsay needs a good sunscreen like DDF Enhancing Sun Protection SPF 30, $32 or Hawaiian Tropic SPF 15 Plus Sunblock, $6.25, which are both faves of TotalBeauty.com users.

Best: Ashton Kutcher
Kutcher's only 31, but his lack of fine lines, sun damage and obvious pores prove he's taking good care of his skin. Though Bank thinks Kutcher may have Botox (due to his lack of crows feet and lines) he believes that his smooth skin texture is courtesy of a good cleansing and hydrating routine paired with regular glycolic and microdermabrasion treatments. Can't afford pricey spa treatments? Try these at-home versions:

Olay Regenerist Microdermabrasion & Peel System, $25.99
Dr. Brandt Microdermabrasion, $45
Neutrogena Healthy Skin Rejuvenator Kit, $38.99

Worst: Brad Pitt
Pitt is one of the biggest heartthrobs in Hollywood, but his skin doesn't always look perfect (shocking, we know). He has obvious acne scars, likely a result of teenage acne. And the overall tone and texture of his skin isn't smooth, which Bank contributes to "getting older, stress or working too hard," he says. Heidi Waldorf, M.D., of Waldorf Dermatology & Laser Associates, recommends several treatments with the Fraxel Restore laser, which costs $750-1500 per treatment and requires two to three days of downtime, to improve scarring like Pitt's.

Best: Cate Blanchett
Blanchett has radiant, glowing skin and a surprisingly small amount of sun damage for someone so fair. "She's done a great job of protecting herself from the sun through sunblock, hats or umbrellas," Bank says. And though Bank admits that Blanchett may have Botox and a filler like Juvederm in her cheeks and lips (watch a woman get both injected in this video), he attributes her nearly perfect skin to religious use of sun protection. Find the best sunscreen for your lifestyle by taking this quiz.

Worst: Renee Zellweger
Sun damage, lack of sleep and stress are what Bank says may be contributing to Zellweger's uneven skin texture and tone. He recommends combating issues like these with products containing alpha hydroxy acids like Neutrogena Pore Refining Cream SPF 15, $13.99 or vitamin A derivatives, found in prescription Retin-A and Triluma, which will lighten and brighten skin. "You can also kick it up a notch with in-office procedures like light peels or the Fraxel laser," Bank says.

Best: Ryan Reynolds
Even at 32, Reynolds has less sun damage and fine lines than most A-listers. Though Bank thinks he may have help from Botox and fillers, he seems to have taken good care of his skin with regular maintenance and sun protection. If you want to get a poreless-looking complexion like Reynolds', Waldorf recommends using a topical retinoid (like the prescription Renova) or an over-the-counter product containing retinol like SkinCeuticals Retinol 1.0, $48. Microdermabrasion used in conjunction with these creams will keep flaky, dry skin away. If you want a more aggressive (but still non-invasive) solution, Waldorf suggests Fraxel for discoloration and pore size (average cost, $750-$1500) and Thermage for sagging, wrinkles and pore size (average cost, $1,000-5,000).

Worst: Mel Gibson
Gibson is no spring chicken, but other celebs his age (like Tom Hanks) seem to have a smoother skin texture and a brighter complexion. Waldorf attributes sun damage as the cause for Gibson's deep-set wrinkles and leather-like texture. "Improvement would take resurfacing (like several sessions of Fraxel), filler (like Restylane, Juvederm or Radiesse) and sun protection," Waldorf says. Have questions about fillers? Get answers here. And don't forget to use a UVA and UVB blocking sunscreen everyday (try Avon ANEW Advanced All-In-One MAX SPF 15 UVA/UVB Lotion, $16.50).

Best: Liv Tyler
Tyler's smooth, clear and acne scar-free face is likely due to a combination of "good genes and great sun protection," Bank says. Though she may have help from Botox, it seems Tyler's been doing all of the right things for her skin (not smoking, sunbathing, picking at her skin or extreme weight change -- all of the things Waldorf says can prevent damage to skin). Make sure you don't commit these seven skin sins either, as they can wreak havoc on your face.

Worst: Teri Hatcher
The flat, stiff smile Hatcher is sporting here suggests she may have had too much Botox, Waldorf says. And her large pores and sunken eyes are possible signs that Hatcher is stressed and lacks sleep. "And being too thin can create or exasperate many of these problems," Bank says. He recommends maintaining a healthy diet and body weight and making use of fillers and treatments like Fraxel and Thermage to tighten and tone the skin. If those options seem extreme, at the very least, use products containing peptides and retinol to help build collagen and smooth lines (try Rodan + Fields Anti-Age Night Renewing Serum, $89.)