If you cannot find the locked rotor amps (LRA) in your motor, a good estimate (for DC motors at least) is to use an milliohmeter and measure the resistance with the motor at rest.
Divide your supply voltage by that number, and there you have it, the stall current. It will be around 3 to 4 times your full load amps (FLA).
If the LRA rating becomes excessive, a good technique to limit the current is to soft start the motor, by using PWM.