There are an increasing number of CPD courses available online and many of them are free. Massive Open Online Courses or MOOCs are run in conjunction with top universities in the UK and USA. For example, I have recently completed a six week course on Assessment for Learning in Stem Teaching led by Dylan William and Christine Harrison from the University of Leeds. The course was free but the optional certificate of completion cost £40 and was posted to me here in Thailand.

MOOC providers include: FutureLearn, Coursera, Ed-X and Open2Study. They are well worth a look.