There are three challenges when mixing concrete: Adding the right amount of water to get the proper consistency, mixing it efficiently, and getting it from the container wherein you mixed it to its destination with minimal wrangling and spillage.
Concrete should be the consistency of oatmeal (but heavier). To test it, scoop some up into a shovel as you mix. If it hangs on the shovel for a second or two before slumping off back into the container, you nailed it.
I mix in a wheelbarrow. It’s just the right height, and whether the project is a deck, fence or sidewalk, I can transport the “mud” wherever I need it without transferring between containers. Pour about half of the water into the wheelbarrow (the amount of water required is 1 gallon for an 80-pound bag.) Then add the concrete mix and the rest of the water — that way the concrete mix absorbs water from the top and bottom at the same time.
My favorite tool for mixing concrete is a garden spade. It moves the right amount of material and helps me mix fast. A hoe (or mason’s hoe) works well, too.
Mixing in a wheelbarrow means I’m ready to place the concrete just about anywhere. When pouring it into a footing hole, concrete tube or around a fence post, tip the wheelbarrow and pour carefully. Sometimes having a spotter here is helpful. And always keep a garden hose handy to splash off any concrete that might have spilled on finished surfaces.