The Teaching Adults service run by Oxford University Press offers a resource bank and subscription to a free newsletter including articles on a wide range of topics also relevant for (EAP and ESP) language teachers. See e.g. the July 2020 issue highlighting further activities such as webinars on online teaching and supporting student collaboration.
Their vision is that teaching adults isn’t the same as teaching children. The learning process is different, and adults usually attend classes for a specific reason, whether that’s to launch a new career, prepare for university, improve their effectiveness in the workplace, or simply get ready for a holiday!