What are the most common (and often overlooked) causes of memory leaks in managed (.net) applications?

Question

Please can anyone recommend a quick checklist / best practice guide to help us avoid simple (but subtle) mistakes that cause could cause memory leaks in .net apps

I find

Answer 1

Check for static variables which don't need to be there in the memory after usage, check for event handling references, any finalizaers which are blocking other finalizers from being collected and also if there are any un managed references to any DLLs or COM+ objects