Bought one.
For the second I bought a regular shirt and pants in a specific color. (He can wear for other outfits later), and an animal hat. He is that animal for Halloween. He is almost two and it is more comfy for him than a big puffy thing. I won't have to fight him to keep it on!

It's just made of things we have. So bought / made? No crafting involved, though.

I always make DD's costumes. I am pretty good with a sewing machine and can make my own patterns. Each costume takes about a month to make and she always wins best costume. She is ten now and begged me for a store bought costume this year (a "real costume" as she calls it).

So much for my work and creativity... but I am off the hook this year and DD will be Ella.

We bought one and DH found various things to cobble together the other one. No sewing, but he pulled it together from various sources.

Somewhere in the middle. I bought a few components, and put them together, so no sewing, but not off-the-rack.

I'm not especially crafty, so I've always bought my daughter's costumes. Or, more accurately, many years I let her dad buy them. Because he's "fun dad" vs. "financially responsible dad" so he spends more money and gets a better costume.

One year I sourced all the pieces to make her into Hit Girl from the movie Kick Ass. I'm crazy proud of that costume. that's the closest I've gotten to making something.

I bought DD's costume for $60 and then she changed her mind and threw something together with clothes from her closet.

I will not be purchasing a costume next year.

Last year and this year we made them; I have fond memories of my mom making mine when I was little. They can be quite elaborate, but I usually don't talk about it unless asked, feels braggy.

Making them, BUT (1) we have one baby who is in bed by 7:00; and (2) they are simple, sewing stuff onto a onesie. Nothing complicated or expensive. Fully plan on buying them when I have less free time or the costume request is more elaborate.

When my kids were really little and didn't know/couldn't say what they wanted, my mom made them some fairly elaborate costumes. Now they are into superheroes and such, so it just works better to buy.

Bought.

Made them. I have this weird thing about making costumes, mostly because it's what my mother always did, I have found memories of it, and I miss her (she died a decade ago). The vast majority of my friends buy them though, and I fully admit that making them is largely a waste of my time.

I enjoy the "sky is the limit" attitude and creativity of coming up with costume ideas with my kids, but there have definitely been years when they wanted to be something "standard" (e.g. spiderman) and we purchased it.

We bought it -

We usually buy them. But last year we made a no-sew ghost costume that he's wearing again this year. Younger kid is wearing older kid's costume from when he was that age.

DS's is usually bought because he always wants some Star Wars or superhero character.

DD's I usually made (now she's 11 and she runs the costume making with me just driving her to the craft store) because she didn't like anything in the stores and had very specific ideas.