I use a foot spray made by Kiwi called Foot Silk. It comes in a small bright pink spray can and is sold in supermarkets with the shoe polish etc. It is like an invisible stocking and prevents friction and foot odour. Your feet just feel nice and smooth, not sweaty, don’t rub and they smell nice. I never used to wear shoes without tights or socks before but it has been a godsend in this hot weather to be able to do without.