Instead of scouring drugstore aisles for the next 'It' eye shadow, some makeup-obsessed tweens are whipping up their own shades, using tiny measuring tools, mica powder and even professional-looking packaging.

These next-generation Estée Lauders graduated quickly from berry-flavored lip gloss and now are dabbling in mineral powder, gel eyeliner and even mascara. They typically work in bedroom cosmetics labs stocked with household products like olive oil and petroleum jelly, existing cosmetics and in some cases specialty ingredients, like arrowroot powder and shea butter. They demonstrate their techniques in front of a webcam and put edited videos up on YouTube.

Sarai Jones, 13, mixes her own makeup in her bedroom at her family's home. Mike Kane for The Wall Street Journal

Creating makeup comes naturally to 8- to 18-year-olds who are more price-conscious and independent, and better-informed, than in the past, says Karen Grant, beauty-industry analyst at market research firm NPD Group Inc. In a 2010 report, NPD noted a drop in awareness of mainstream brands among tweens, a sign they are experimenting at home.

Some of these self-styled "beauty gurus" count thousands of YouTube subscribers, and their five- to 10-minute videos can each get as many as 100,000 hits. Some dream of following the paths blazed by two early YouTube cosmetologists, Michelle Phan and Koren Zander, who parlayed popular how-to makeup videos into lucrative sponsorship deals.

Sarai Jones makes cosmetics from common household products and specialty ingredients. Mike Kane for The Wall Street Journal

Retailers have responded with inexpensive products that young consumers can modify. GeoGirl, a beauty line carried at Wal-Mart, encourages layering of lip products (about $4.29) for a more-customized look, says Janine Coppola, senior marketing director of Pacific World Corp., which makes the line. The Love & Beauty cosmetics line sold by Los Angeles retailer Forever 21 Inc. has expanded its eye palettes (from $1.50) to encourage mixing, says Linda Chang, senior marketing manager. The retailer also offers 15 types of glue-on eyelashes (from $1.00).

The household products and ingredients for the cosmetics Sarai makes. Mike Kane for The Wall Street Journal

Cloe Feldman, a 14-year-old in Florida, combined a dark, $1 eye shadow with Vaseline to create gel eyeliner. She packed it in an empty makeup-counter jar and put on a homemade label: "Cloe Cosmetics gel eyeliner in Midnight." Her video of that creation, with more than 22,000 hits, is now the most popular on her YouTube channel, CloeCouture, which counts more than 4,000 subscribers.

Cloe says she plans to build her subscriber base by making more do-it-yourself videos aimed at viewers who often can't afford to buy make-up.

Cloe says she knows her audience is growing. "I have braces so I don't have many subscribers, but it's happening," Cloe says. Her newest concoction is lip jelly made from honey, petroleum jelly and pink eye shadow.

Eye Shadow by Sarai Jones Materials: 1/4 tsp mica powder pigment, any color (combine several pigments to get the desired shade)

1/4 tsp arrowroot powder (a powdered cosmetic-grade starch similar to talc)

1/8 tsp magnesium stearate (powder that helps keep ingredients from separating)

3 drops castor oil

Eye shadow container

Bowl

Mixing spoon or electric mini blender Directions: Combine mica powder, arrowroot powder and magnesium stearate in bowl. Mix until consistency is even. Let sit for five minutes. Add castor oil and mix until consistency is even. Scoop mixture into eye shadow container and pat flat.

Some junior cosmetologists have jaded views about high-priced cosmetics. Rachel Levin, 16, says Urban Decay's eye shadow primer doesn't need to cost $19. The product—a light foundation to keep eye shadow from creasing—is essential for her beauty routine, but she says she can't afford it. So she makes her own using concealer and body lotion. Another favorite is make-up brush cleaner made of shampoo, conditioner and isopropyl alcohol. She is perfecting a pumpkin face mask for Halloween.

Katy Wilhelm, 17, created pore-cleansing strips out of egg whites and tissues, to help eliminate blackheads (her YouTube video shows a close-up of the used tissue). "It's all about experimentation," says Katy, who no longer buys Biore's $8 Deep-Cleansing Pore Strips. Previous generations were too obedient in their beauty routines, she says. "If it was lipstick, they'd put it on their lips…but lipstick is a good tool for creating rosy cheeks."

Sarai Jones, 13, is set to turn her makeup into a business when she starts selling her products on her own website this month. She has recently been testing out her own concoctions for foundation bases and primers in hopes of selling a long-lasting version similar to one from MAC Cosmetics.

Gel Eyeliner by Cloe Feldman Materials: 1 tsp dark eye shadow or pigment

1 tsp of Vaseline

Small container with lid

Toothpick

Plastic spoon

Paper plate Directions: Scoop out eye shadow onto paper plate with toothpick. Add equal part Vaseline with spoon. Continue mixing with spoon until it is well blended on the plate. Scoop into small container.

"I want a concealer that's full-coverage but not too cakey," says Sarai (pronounced sa-RAY). She has mineral pressed powder and blush in the works.

Sarai says her mom has allowed her to wear light cosmetics since sixth grade. "Technically, my mom got me into makeup," Sarai says. She sometimes still browses through her mother's makeup for inspiration.

NPD's Ms. Grant says many times mothers influence their daughters' makeup habits, with the result that more tweens reach for brands that adults use, such as CoverGirl, instead of starter brands, like Bonne Bell, which have lost market share in the past 10 years.

Lip Jelly by Cloe Feldman Materials: 1 tsp of Vaseline

4 drops of honey

1 tsp of eye shadow or pigment

5 drops of liquid food coloring, or a pinch of powdered food coloring Directions: Mix Vaseline and honey on a paper plate. Add food coloring and pigment. Stir to get a thick, even consistency. Use toothpick to scrape product into jar. Editor's Note: Never modify old cosmetics. Use clean tools and containers to prevent contamination. Homemade products can spoil easily.

"The role of mom is critical," Ms. Grant says. "A decade ago, they were not trusting mom." Tweens are counting pennies, she adds, asking "Do, I really need to buy this, or can I mix this?"

Noting the demand for DIY cosmetics, Rebecca Midkiff, a mail-order entrepreneur based in Tucson, Ariz., founded Diycometics.com in 2004, where mascara containers sell for $11 for 10, a minigrinder for mixing foundation sells for $13.95 and iridescent mica powder sells for $5.15 an ounce.

DIYcosmetics has set up a sponsorship relationship with Sarai Jones, providing some products for her videos. Recently, Ms. Midkiff says, she has noted an uptick in mothers buying supplies for DIY makeup parties.

Write to Alina Dizik at alina.dizik@dowjones.com