The most common pattern lock is the simple diagonal pattern that starts from one corner of the screen and ends at the opposite corner. This is because it is easy to remember and can be drawn quickly with one hand. However, using this pattern as your lock screen can be a security risk since it is easy for others to guess or observe the pattern. It is recommended to use complex patterns or other types of locks, like the alphanumeric or biometric locks, to increase the security level of your device.