There are several ways to clean golf clubs. You can spend a little money on golf club cleaning kits that are available in many golf pro shops and online retailers:
Shop Amazon for golf club cleaning kits
And those cleaning kits do work well.
Or you can simply gather up a couple household items. What you need is a plastic bucket (unless you're willing to clean your clubs in a bathroom or kitchen sink), a mild dishwashing detergent, an old toothbrush or other brush with soft plastic bristles, and an old towel for drying.
Squirt a little of the dishwashing liquid into the bottom of your plastic bucket, then add warm water to create suds. Make sure the water is warm, not too hot (very hot water can loosen the ferrule on golf clubs).
You only need enough water in the bucket to cover the heads of your irons.
Place Your Irons in the Bucket
Place the bucket, with its water and suds, near your garden hose (if you don't have access to an outdoor water source, work inside in a deep sink or even a bathtub).
Set the bucket down, then place your irons in the bucket with the clubheads submerged. Notice in the photo how the clubs' ferrules are above the level of the water and suds.
Allow the irons to soak in the warm water for just a couple minutes.
This will help loosen dirt in the grooves of the clubface, and allow the suds to begin working on oils and golf course chemicals that are on the clubheads.
Clean Out the Grooves
After a couple minutes of soaking time, take each club in turn and use an old toothbrush (or other plastic-bristled brush) to clean out the grooves on the clubface. This is the most important step in cleaning your clubs - removing all dirt and debris from the grooves.
Also drag the brush across the sole of the iron and over the back of the clubhead, removing dirt, grass and other debris.
A soft-bristled brush should work fine.
If you've allowed dirt to build up in the grooves and harden over time, you may need to allow more soaking time and then use a stiff-bristled brush. Never use a wire-bristled brush during cleaning, because this can scratch the surface of the clubface.
Rinse Off the Clubhead
Use your garden hose (or tap, if you are working indoors) to rinse off the clubhead. When the suds are washed away, take a look at the club to make sure all dirt is removed from the grooves. Be careful not to splash water up the shaft.
Use your old towel to dry off the clubhead. Also drag the towel up the shaft of the club. This will remove any loose debris from the shaft and also ensure that the shaft doesn't go back into your bag wet.
It's a good idea not to submerge woods under water, and especially not to let the soak, because they usually have a nice, glossy finish.
Instead, quickly dip metal woods into the sudsy water, wipe down with a moist cloth, then dry with a dry cloth. Use a moist cloth to clean off persimmon clubheads, then dry immediately. If there are grooves on your metal woods' clubfaces, and those grooves retain dirt or debris after you've wiped down the clubface, it is OK to use a soft-bristled brush on the grooves only.
If you are one of the very rare golfers who still owns and plays persimmond woods, do not submerge wooden woods in water. Instead, wipe them down with a moist cloth, then dry.
See also: How to Clean Golf Grips