You want the cutoff frequency of the LC filter,
\( f_0 = \frac{1}{2 \pi \sqrt{L C}} \)
much less than the PWM frequency. Then the high frequency energy will be filtered (and the bridge will see an inductive load, which is good for its operation), and you can connect to the motor with long wires, without worries of causing radio emissions, or overheating the motor.
You also want the impedance of the filter,
\( Z_0 = \sqrt{\frac{L}{C}} \)
close to the impedance of the load, i.e., whatever the average \$\frac{V}{I}\$ is. If this resistance is not present around \$f_0\$ (that is to say, if there's no resistance at that frequency, due to it being filtered, like due to the motor's stray inductance), you should also add an R+C in parallel with the capacitor, \$R = Z_0\$ and \$ C \geq 2.5 \$ times the first C.
Tim