a) The main uses for cavalry include:
a1) reconnaisance (to probe the enemy for weak and strong points);
a2) to screen an advance (placing cavalry slightly ahead of your main force will screen your troops from the enemy);
a3) to screen a withdrawal (by attacking an advancing enemy at strategic points);
a4) as shock-troops.
b) Initial deployment should be:
b1) ahead of mian force (to screen an advance);
b2) on flank(s) of main force if flank(s) are not protected by terrain.
c) After initial contact cavalry my be used to:
c1) cover flank(s) as indicated in (b2) above; and/or
c2) act as a reserve (to later fill in gaps in your line); and/or
c3) act as shock-troops where the enemy has revealed a weakness.
d) Casualtes to your cavalry must always be minimized as fas as possible (Remember that cavalry units are small, but present large targets. It is therefore important to use tarrain and/or large infantry units as cover against especially enemy artillery or other massed firepower.)
e) Cavalry is best used in relativbely open terrain where their manouvrebility can count for them.
f) Specific cavalry tactics include:
f1) The impied threat (Let the enemy know yu are there, but stay out of his reach. This tactic works especially well against unsupported infantry.)
f2) Use as mobile infantry or artillery (WWII).