Dramm Heavy Duty Brass Garden Hose Shut-Off Valve
Dramm's solid brass shut-off valve is a superb way to control water hose flow from the end you're holding. Unlike the cheap plastic valves you'll find at big box hardware stores, this one is durable enough to last you for years rather than a season or two. The ergonomic handle requires only a quarter turn clockwise to turn the water flow completely off, so it's easy to do even with wet hands.
Get it for $21 on Amazon.