The tip of pronouncing ' zh ':
First you raise the tip of your tongue to touch the front area of your hard palate. Then you loosen the contact and a narrow gap is formed, and at the same time you blow air through the gap to make the sound of ' z '.
As for ' ch ', the method is the same as for ' zh ', and try to make the sound of ' c '.
The tip of pronouncing ' sh ':
First you raise the tip of your tongue to be close enough to the hard palate to form a narrow gap. Then you blow the air through the gap to make the sound of ' s '.
The tip of pronouncing ' r ':
The method the same as for ' sh ', but you may notice that ' r ' is a voiced sound, while the other three are voiceless sounds. So you can feel the vibration of your vocal cord when you pronounce ' r '.
The sound of ' y ' is the same as the final ' i ', but comparatively shorter. The sound of ' w ' is the same as the final ' u ', also the sound lasts shorter than ' u '.
Till now, we finished all the lesson of the Pinyin initials. Notice that there are only four initials are voice sound, they are: m, n, l, r, while the other initials are all voiceless.