Reddit mentions of 50 Jars Beauticom 3 Grams / 3 ml small Plastic Jar - Premium Quality Round Clear containers with Lid for Cosmetic Lotion Cream Makeup Beads eye shadow Pot sample travel Containers (Clear Lid)

I don't know of any indies that make pencil eyeliners. There are some that do gel liners, which I think are the best of both worlds...the control of a pencil, the smoothness of a liquid. I'm pretty sure I've seen some from indie brands, but I don't own any. Maybe someone else has more info on that.

You need brushes, but they don't have to be super expensive. I use EcoTools and Elf brushes which you can get in drug stores. They do the job fine. Brushes with short, stubby bristles are better for packing on pigment, I usually use this for my main lid shade, softer brushes are better for blending, and narrow, stiff brushes are better for precision application.

As for eyeshadow...first eyeshadow primer sounds like a stupid product, but it will make your eyeshadow last all day without creasing or falling onto your cheeks. I like Eccentric Cosmetics primer, but Wet N Wild's Photo Focus Eyeshadow Primer is pretty good, is $5 and you can buy it almost everywhere.

Most indie brands only offer loose shadow. A few have pressed shadows, but they cost more and you can't get pressed samples. If I were you, I'd get a few mini jars or samples (indie shadow samples come in plastic baggies, it's easier to use them if you dump them into these). Choose a few dark colors, a few medium colors, and a few light colors (colors significantly lighter than your skin to function as highlights), since you're just starting, I'd recommend going for "neurals with a twist" because it's easier to do cohesive looks with a more or less neutral pallette. Shiro is often recommended to beginners, they have a wide range of colors and finishes and very inexpensive samples, My Pretty Zombie has fewer colors but you can get sample sets sent letter mail which cuts down the cost. Watch some basic eyeshadow tutorials on YouTube (I don't follow many makeup channels, perhaps someone else can chime in) or find some blogs with pictures and instructions like this or this and just practice.

Sample containers:
௳ The bottles with the green flip-caps are from Amazon (~0.5oz/15mL each, $21.99 for 36).
௳ The little pots with screw-on lids are also from Amazon (3mL each, $7.99 for 50). I wound up making 2 pots for each sample because they were a little smaller than I had imagined (Starfish Lord, grant me the presence of mind to look at dimensions before ordering things), so next time I might get these slightly bigger ones (5mL each, $10.00 for 50).

Decanting supplies:
௳ I used these plastic transfer pipettes (3mL, $4.50 for 100) to decant anything that I could suck up with them.
௳ Anything in a pot was decanted using these wooden spatulas ($22.98 for 500); I put 2-3 in with each potted sample and kept the rest for myself. (Forgive me, my Spiny-Skinned Savior, for lacking the diligence to wash and dry my plastic spatulas after each use; pray accept my disposable compromise or guide me to a better way).

Baggies:
௳ The small ones are from the Container Store (2.5” x 3”, $0.89 for package of 10).
௳ The larger ones are from Wegmans, but similar ones are available at Target (3.5” x 5.5”, $2.24 for 64).

Markers:
I tested a lot of different markers before I found some that didn’t smear/smudge/wipe-off and that could withstand the watery trials of the bathroom counter. From my own stash, these three worked:
௳ Gold: Montana Acrylic Extra Fine Point (0.77mm) Marker in Matte Gold (Metallic) (available from Dick Blick for $5.35).
௳ White: Sharpie Oil-Based Paint Extra-Fine Point Marker in White (available from Joann for $2.62).
௳ Teal/peacock blue: Derwent Graphik Line Painter (acrylic, 0.5mm) in Brilliant (available from Dick Blick for $3.96).

seconding this I use these 3g jars and they work pretty well! I purchased from this seller twice and haven't had any issues with any of the jars so far.