Gather fabric, snap fastener, snap setting tool or pliers, hammer, awl or fabric marker, and stabilizer if needed
Mark the exact placement of each snap half on the fabric
Reinforce the fabric with interfacing, felt, or a small patch if the fabric is thin or stretchy
Make a small hole at the marked spot using an awl or the snap tool
Insert the snap prong or post through the hole from the correct side of the fabric
Place the matching snap part on the opposite side as directed by the snap type
Position the snap setting tool over the snap pieces
Press firmly with snap pliers or strike the setting tool with a hammer until the snap is secured
Repeat for the other snap half on the matching fabric piece
Test the snap to make sure it closes and opens securely
Reposition and reset the snap if it is loose or misaligned