I'm not envisioning all mixed together, but maybe a sewn cloth flag garland that says something like, "happy circleness!" and some colored paper flag garlands to criss-cross about the home.
I found this photo of happy garlands to illustrate an idea of what they could be...of course circleness has a color theme, and while I'm not exactly sure of what that is, blue is definitely involved. a cerulean blue is what I have in mind. I'm thinking it represents sky and water...I think a more muted blues will also be involved in the color scheme. I'll post that as soon as I get it worked out.
