Elementary inferences about pairs.
One way you can count the low cards, in addition to counting those
you can see faced on the table (plus, of course, your own hole
card(s), which, let us hope, will be low!-see number 1),
is to infer pairs. Why did Smith, with nothing but nice juicy
low cards on his board, drop out on that round? The answer will
almost always be that Smith's last card paired his hole card!
Thus, if a player starts with a five exposed, then draws a three
and drops out during that betting round, it's dollars to doughnuts
he has a three in the hole.
Such an inference, while easy enough, can be of considerable value
in counting the low cards. These special pointers, plus the general
techniques dealing with bluffing, position, etc., covered previously,
should give you a flying start in any low stud game. The rest
is experience in judging hand values and general poker technique
and psychology.