Hmmmmm
My advice is to build them sectionally laying down each element in the order they are raised on the model. So, first the ribbon trails, then the bow loops and finally the knot.
I would roll the putty flat and make a few thicknesses. Leave it to go slightly hard as green stuff remains very flexible after it has started to set, then cut it in to strips with a scalpel and ruler. Use slightly thicker strips for the trails and then then take a thinner strip and leave it to harden further before bending it completely over to make the loops. Finally either take two thin squares of GS and lay them on top of each other at an angle to simulate the knot or just a small blob of fresh GS if you want to cheat. The knot essentially hides where you have glued the other elements together.
This would be how I would do it. I’m sure there are plenty of methods and I am by no means an expert.