By scale Practice Only we can free our finders while playing piano/Harmonium or any melody instrument for that matter.
What is Scale Pracrice?
For Example, when we Practice C Major Scale,
We have to play the following notes on piano:
C D E F G A B C [ascending]
C B A G F E D C [descending]
However the findering must be very correct which only makes you a great player.
The fingering for the above scale is as follow:
C1 D2 E3 F1 G2 A3 B4 C5 [ascending]
C5 B4 A3 G2 F1 E3 D2 C1 [descending]
Where C1 means we play the C note here with Thumb,
B4 means, we play B note here by ring finger.
Thumb=1
Index Finger=2
Middle finger=3
Ring Finger=4
Little Finger=5
P.S: There are 12 major and 12 minor such scales and many more scales. Above mentioned exercise is one of them.
ALL The Very best with your Practice.
Good luck.