I had a nice email last week from Jonathan of the Norwald chess set makers from Denmark, who has offered us a guide to get better at blitz chess.  It's long and thorough -- thank you Jonathan!
The original is here https://norwald.dk/en-intl/blogs/artikler/how-to-get-better-at-blitz-chess, a copy is given here https://devonjuniorchess.co.uk/wp/drdaveexeter/2026/10/12/a-gift-to-blit... , and their other articles are here https://norwald.dk/en-intl/blogs/artikler