I am a firm advocate of large-scale Celtic knots. I believe in Celtic knots that can be recognized and appreciated from across a room.
I used to position fabric shapes with a bit of space between them to give the illusion of a stencil to my Celtic knots. The spacing uses artistic convention and visual perception to give the illusion of woven lines.
Now, I weave flat-fabric loops together to achieve my Celtic knots.
Three intersecting Celtic knots (note the various corners)Path OnePath TwoPaths Three and FourPaths Five and SixPaths One and Two, combinedPaths One, Five, and Six, combinedPaths Two, Three, and Four, combined