Lots of things slow down in summer. People are spending money on their vacations and the local festivals (some buying crafts, no doubt!) and such.
Didn't Etsy have a marketing/advertising campaign a short time ago, which resulted in excitement and sales? Well, that campaign is over! Time for the next one. It's also up to you to market your site. Having a website doesn't guaranty any sales.
You could always check out your local community education program to find out if you can teach a class. You could provide a class through them, or through a community or neighborhood center. It can be an adult or a kids' class. Moms might look for something fun to do with little Billy or Suzy.
If you're art savvy you might work p/t at a local craft or art supply store.
You might approach daycare centers to see if they would offer a special class, featuring you.
Churches in my area won't offer anything that makes a profit (state law, apparently). Yours might be different.
Approach Red Hat Societies. They're always looking for something fun to do, and they'll pay you.
My favorite is to make a basic bread pudding, and bake in some inserted fresh raspberries and white chocolate chips. The mix up some ganache (equal parts of cream and white chocolate melted together) to drizzle over. Nummy!
Even after you submit it, it'll take many weeks for it to kick in, so the sooner you submit your site to the search engines, the better.
Keywords and tags aren't enough these days. You have to work your keywords into your page text. If you sell handmade items, the words handmade should show up on your front page somewhere (instead of "made by me", for example).
Also, retain your copyrights. Get an agreement done up allowing them the use of your pattern, but to keep the right to use - and sell - your pattern elsewhere. If they want all rights to the pattern, you should charge them more to take it from you.
The first thing that comes to my mind is embroidery hoops and springform pans, and although I'm not sure how the pans would work, you might be able to use the same kind of latch to tighten things up. Other that, some other mechanics would have to be involved, and I'm certainly no expert!