Sorry fat fingers! Pressed 'Add message' by mistake in my last entry. How to get invited? - The painstaking way - by becoming known in the field, presenting at conferences that the 'editor to be' has seen you at, maybe through contacts e.g. knowing your supervisor etc etc. I may be wrong but I don't think you can actively pursue an invitation as such - it happens in time with actively promoting your work. This has been my experience - others may have had different experiences.