How to unclog shower head holes and increase water pressure

To clean a removable shower head:

Remove it from its place and place it under running water, but upside down (the holes must face the water jet).
Rinse until surface residues of limescale and dirt are removed.
Soak the shower head in a container full of vinegar overnight.
The next day, scrub with a toothbrush, then rinse it as done in point 1.
Now that you know how to unblock the holes in the shower head, try applying this method immediately to return to having satisfactory water pressure.