My daughter loves her little lego figures (these are technically lego "minidolls," but they're made by lego and compatible with lego bricks). She now has every single lego princess, and all of them need ball gowns!
I've found a quick and easy way to make durable little lego dresses, and it requires extremely minimal sewing skills. You can make these with any type of fabric and thread, so it's a good use for fabric scraps. I have found that the easiest material to work with is felt. I like the wool felt because it's natural, but any felt will work.
This method should also work for making dresses for traditional lego minifigures, but you'll probably want to tweak the pattern a bit (a bit smaller circle, with a slightly larger, oval-shaped hole for the legs.)
Step 1: Find a medicine jar lid.
It should be about 2.5 inches in diameter.
Step 2: Trace it onto fabric of the desired hue.
If you use white felt, you can actually give it to the kids to color with permanent or washable markers. This makes a fun way for them to easily customize their dresses!
Step 3: Sew a running stitch
Sew a simple running stitch all the the way around the circumference of the circle. (If you aren't using felt, you'll want to either hem or blanket stitch around the circumference before doing the running stitch)
Step 4: Pull the thread! Pull the thread until you get kind of a mushroom shape. Then tie a knot or two to make sure it doesn't unravel.
Step 5: Cut a small hole in the center of the dress.
I like to fold the dress into quarters and then snip the tip. If you're making this for a traditional lego minifigure, you'll probably want to cut an oval, rather than a little hole.
Step 6: Put it on the doll!
To customize them even futher, you can embroider or applique designs, sew inserts of other fabrics, color with markers, sew on beads, whatever your creativity inspires!
I just asked her what her favorite is, and she said, "All of them!" She can't decide!
The reason the green one is so elaborate is because I was trying to make her a Tiana doll. They haven't released a Tiana lego in many years, and so the doll alone is a good $25+ on the secondary market. So I tried to cobble one together from the pieces I could find. To make her look like Tiana, I actually hand dyed the cloth to make it more of the green, and embroidered on the white lily. It was totally worth it to see her face on Christmas morning when she got her own Tiana!
Two days ago, she decided that she needed a Princess Peach (from Mario) and a Princess Zelda (from the video game) so we used her left over pieces to make the princesses. But, to make them look like themselves, I made them fancy skirts! (Princess Peach is usually in pink, but we didn't have a pink shirt piece, so this Peach is blue...)
We actually started out using paper, and it was a lot of fun for the kids to design and cut it out. But, the paper wasn't very durable and tended to rip and fall apart easily. The creases weren't that easy to make look good, and tended to uncrease.
This was actually the tutorial that we first used:
The paper hole punch idea is great idea for making nice, clean holes just the right size. We cut our holes by hand, and they didn't always fit quite right!