Strategies:

Here is a great evidence-based article on strategies for managing oversupply, including some how-tos for block feeding:

Forceful Letdown and Oversupply via KellyMom

Tools:

Some moms who have an abundant supply find that they also leak milk. Some really like this product for catching the leaking milk for storage. Note in the reviews what others have told me – they catch milk, but are also big!