It might surprise you to find out just how important getting the right grind is. Whereas a french press requires a courser grind, and is very forgiving, espresso machines require a grind that is very specific. Get the right grinder and maintain it. A mediocre grinder will lead to under extracted espresso and even alter the flavour by exposing the coffee to high temperature. Too many fines, and poor distribution of grounds will leave a bitter taste in your mouth.
Regardless of the grinder you have, the most important aspect to any grinder is sharp burrs. If your grinder has sharp burrs you will create less stress on the motor, generate less heat, and make fewer fines. Depending on the model and age of your grinder new burrs will be easy to find and make all the difference! Let us know if we can help!