I have a whetstone, faucet and a knife, but never quite get the results I want. So Cook with E’s guide to using them (“the only time I’ve ever seriously hurt myself in the kitchen was using a dull knife”) has sent me right back to the kitchen.
Ethan recommends a fancy japanese model, but I have a less expensive Whetstone-brand stone [Amazon, but I got it from Williams-Sonoma] with both 400 and 1000 grit sides.