Beginnings of a miniature painting rap by the wonderful @equanimousbosch.
What are your favourite burnishers?
I do tend to 'collect' painting stuff so will post some pics when they are all gathered in one place!
The other thing is you can use found stones and other smooth objects as burnishers, as long as you test them thoroughly first so they don't streak. Or - just burnish indirectly through parchment paper/greaseproof paper/baking paper/thin tracing paper at first and save the direct burnishing for the specifically made art material ones.