I first discovered mat faced good luck knots about a decade ago on the decorative Chinese knotting site, zhongguojie.org. There, of the examples I have seen, the mats used are invariably flower hoop knots (花箍结) otherwise known as cylindrical braid knots or more commonly as turks head knots. I have not seen a name for this class of knots in aggregate, but I have been calling them mat faced because I think any mat will work. The names I have seen generally follow the formula of 8B9L good luck knot.

Supplies

This is an advanced decorative knotting technique, so I will simply say, any appropriate cordage will do. I'm using 3mm satin cord, approximately 2m for the main example.

cord
scissors
paper

Step 1: The Mat Face

If you want to tie a cylindrical braid knot for your mat, I have an Instructable here with pointers to find instructions plus quick and easy tools to make out of paper or cardboard and nails. For variety and to test the aesthetics of my theory, I'm going to start with a pentagonal kringle mat (overlapping variant), also called a yetter mat using this convenient online tool (note that the black bars are sliders and if you move the Segments slider you can effectively generate a step by step).

Step 2: Expanding Bights

The next step is to expand the outer bights of the knot. Extend them enough to tie a good luck knot (GLK). You can do this if you are very careful to track and control the centre structure of your mat... while tying your good luck knot. This does not always go well, so I like to take out some extra insurance with a paper template for cord management. Simply punch as many holes into a scrap of paper as you are planning to have arms of your good luck knot, then extend the bights into the holes

Step 3: Pentagonal Good Luck Knot

The instructions for square Good Luck Knots are widely available. Let's show a pentagonal good luck knot. Note that this is a spiral version of the good luck knot vs the traditional box as we are not reversing the direction of rotation for the second layer.

Here, instead of overlapping one neighbour, we are overlapping 2 for a tighter central structure.

arms 1-3 go over 2
4th arm goes over 2 and through 1
5th arm goes over 2 and through 2
tighten up the first layer. untwist arms if necessary
repeat the above for the second layer

Step 4: Tightening the Knot

Tightening and truing up a mat faced good luck knot is tricky due to there being 3 layers:

loose end/loop layer (good luck face)
hidden layer which is the back of the good luck knot
mat layer (mat face)

the folded end of an ear loop is easy to see from the GLK side.
the cord path through the mat side is also easy to see
when pulling slack from the folded side of an ear loop, it is important to remember that the cord will be traversing the hidden layer to just above the ear loop where the GLK joins to the mat

Step 5: Mats and Luck

The first 2 pictures here are our pentagonal kringle/yetter-GLK. The purple tinged white knot is a 5B4L flower hoop-GLK. The last is a plum flower knot 梅花結 / woven faced good lucked brick stitch knot.

So, use any mat knot that you would like. You don't have to use all the mat's edge bights for your GLK. Remember that any crown-style sennit, including most scoubidou/lanyard/boondoggle stitches can be a good luck knot.