When my son was younger, this was the time of year that he and I most looked forward to. He would have a costume in mind and I would get to figure out which components we were going to make, and which we need to buy.
Once, I made this clown costume from scratch, but purchased the wig and make up.
Another year, we bought the whole Santa outfit, but I assembled a crafty undershirt strategy that contained a jolly-sized belly. (Hard to see in this photo.)
Here's where to buy costumes and materials to make them yourself in the East Bay.
Second-hand clothing stores. In October, Goodwill, Salvation Army, and other thrift stores sell used, but originally store-bought kid's costumes. but they also have the makings for tons of homemade costumes. An old prom dress can become a princess or fairy. If you have low-level sewing skills, it's easier to start with a manufactured garment and leverage the existing hems or zipper closures.
Kids used clothing stores start putting their costumes out during the first week of October. I stopped by Grove Street Kids and they are already ready for you.
Check out the following used clothing stores for baby, toddler and preschooler sizes.
Chloe's Closet (Albany)
1545 Solano Ave
Grove Street Kids (Berkeley)
1385 Shattuck Ave
Ruby's Garden (Oakland)
5026 Telegraph Ave
Bring your costumes in from last year and trade it in for credit!
Seasonal Halloween Spirit Superstores. These pop-up shops enable landlords to earn some rent while occupying a vacant retail space. This year you'll find a warehouse-style Halloween store, packed with costumes, accessories, and house decorations in these locations:
There are two stores in Emeryville: Bay Street Across from Old Navy and the Powell Street Plaza (where Trader Joe's is)
El Cerrito Plaza, near Petco
San Leandro, Bayfair Center
Party City (Alameda and Richmond)
I recently extolled the virtues of Party City for Halloween.
Fabric stores sell patterns for sewers, fabric, yarns and notions. DIYers will find light green furry material for Oscar the Grouch, silver fabric for a knight's cape, or velcro that will be easy to install. Try one of these:
Jo-Ann's (El Cerrito Plaza and San Leandro)
Make sure to download their app before you go for coupons
Michael's (Emeryville, Alameda, Pinole)
Less fabric, but more posterboards, sticky back felt, and adhesive products.
Stone Mountain & Daughters (Berkeley)
Knowledgeable staff who can help you strategize your craft project
Deep discounts can be found at the fabric outlet on San Pablo and Ashby.
East Bay Depot for Creative Reuse. This Temescal shop is filled with supplies that have upcycle potential. Yarn, plastic containers, jars, magnets. If you can convince your kid to be a robot, you'll definitely want to get inspired here.
Related: A whole web of ideas for baby and kids Halloween costumes on our other site, Rookie Moms.