The first thing I did, which I did not photograph was to cut a piece of tulle bigger than my hoop, stretched it in the hoop and stitched the mandala to it. Don't stretch your tulle too tight or it can tear. The stitching is a bit fiddly when trying to get the work to reach the edges but I did settle into a rhythm with it. I chose to only anchor at the outside edge but if you were concerned about stability you could of course anchor at every round if you wanted to. Just use the same yarn as the round you are securing and a wool needle for this. You will see my navy stitches just inside the hoop edge on the back of the work.
Once your mandala is anchored on the tulle in the hoop trim the edges of the tulle to leave an overhang of a few cm. Ideally you want it to reach around and almost touch the back of the work, with very little overhang. Next you line the inside of the frame with a strip of good quality double sided tape. The tape should be more than half the width of the frame, or use two thinner strips to get the width. I used Scor-Tape.
When you have the whole frame taped remove the backing strip and start to pull the tulle down onto it. Again be firm, but not too tight or your tulle will rip, you want a neat edge. Some areas will have slightly more bulk with the gathers but that's Ok just spread it as evenly and neatly as you can.
To finish it and seal the tape I added a strip of coloured washi tape over the top. This is not essential however it will stop any dusty friends landing on and sticking to that Double sided tape you have anchoring the tulle. It also just gives it a 'finished' look which is especially nice if you are gifting.
The tulle is barely visible unless you are at close range, I actually used Blush colour Tulle too but you cant tell its pink in a single layer. I tried this with a double layer but I wasn't happy with it. The last thing I did was run a band of patterned washi around the outside of the frame to give it a bit more pop, the frame being drab did not sit nicely with the awesome sunshiney, happy bringing, goodness of the mandala, so I gave it a spotty coat.