make your own starch if you didn't go a bit bonkers and buy a 3 pack of starch you didn't really need like I did some years ago..
|Tula Pink's Meteor Shower|
I just traced the shapes with paper for templates, then cut the fabric out. I sprayed starch on the glass and and the light fabric just stayed right where I put it while I sprayed another heavy mist on top. It's a bit lopsided since it's temporary, but *shrug*.
I thought I'd do a window in the kitchen while I was at it, after I forgot to close the blinds and found myself being surprised by my neighbor pretty nearby in his yard (I was wearing clothes though, phew!) I chose Tula Pink's Birds & Bees Meteor Shower in Cinnamon, but will probably switch to something less opaque soon once my fabric is all unpacked, since I could use as much light as possible in the room I spend so much time in!
Heavier cotton fabric means it's good to spray the window AND douse the fabric with starch before you put it on the glass.
A squeegee can help you work out any air bubbles, and if you're a bit off in your measuring you can carefully use an Exacto knife to trim any excess.