Identify the source of the squeak by walking on different surfaces
Remove the insoles and check for rubbing or loose fit
Sprinkle baby powder or cornstarch under the insoles
Apply a small amount of talcum powder between noisy layers
Lightly sand smooth any rough spots on the outsole or midsole
Tighten loose laces to reduce internal movement
Add adhesive pads or moleskin to areas that rub
Use a leather conditioner on leather shoes
Dry wet shoes completely before wearing them again
Replace worn-out insoles
Check for loose outsoles and have them repaired
Use a small amount of silicone lubricant on external rubbing points
Avoid over-wetting the shoes when cleaning them
Break in stiff shoes gradually
Take the shoes to a cobbler if the squeak persists