You can try as follows:
Inline Skates. In this stop, stretch your hands out in front to maintain your balance while bending your knees a little. Then, push the right skate forward (the one with the brake) as you lift your toe and lower your heel. To make doing all this feel natural and less challenging, try to sit in an imaginary chair below your bum. Also, avoid bending too far forward or standing straight up.  Now, in that nice and low position, put your heel down hard until it touches the ground/road. The friction between the brake and the riding surface should eventually bring you to a stop.
Quad Roller Skates. Put a skate perpendicular to your direction. Your perpendicular skate  front wheels come into contact with the ground and participate in braking. The other skate stays in line for smooth braking. Your bent knees help you to be flexible.
Ice Skates. In this stop, stretch your hands out in front to maintain your balance while bending your knees a little. Then, push the right skate forward (the one with the brake) as you lift your toe and lower your heel. To make doing all this feel natural and less challenging, try to sit in an imaginary chair below your bum. Also, avoid bending too far forward or standing straight up.  Now, in that nice and low position, put your heel down hard until it touches the ground/road. The friction between the brake and the riding surface should eventually bring you to a stop.