Unless you've signed up for a tap-dance class, your shoes should not click or make loud noises when you wear them. Hard plastic soles may be the culprit, but noisy embellishments like a tassel or metal-tipped laces could be causing the clicking sounds too. You can soften or diminish a shoe's clicking sound by making minor adjustments to the shoe or its embellishments.
Look at the end cap on a high heel that clicks. If the cap is missing, an exposed nail may make the shoe click when you walk.
Put your shoe on and stand up; look at the heel. You should not have more than 1/2 inch of space between your foot and the back of your shoe. A loose shoe, including a strapped shoe, will click when you walk. Adjust the strap for a closer fit, if possible.
Look at the shoe's embellishments, such as tassels or buttons. Tap the embellishments with your finger. If they move, they will click when you walk. Remove the embellishments or secure them in place with hot glue.
Take your shoes to a shoe repair shop and have the soles replaced with a rubber sole. Rubber soles muffle walking sounds and provide some shock absorbency.
Walk slower to make clicking sounds less prominent.