Clean the shower head correctly.
If your shower stream seems to be weaker than before, you might have hard water: in this case, the minerals are jamming your shower head and nozzle. Use a toothbrush soaked in white vinegar to scrub the water jets. After that, wipe it and turn on the jets to maximum to get out the clogging minerals.
Saves on flashlight batteries, too.
Use a damp paper towel.