It should be very simple: opening bank + sales (which is the x or z number) - payouts - charges(because they're in the x/z but not in the drawer) - returns/loss - closing bank = the drop. don't forget to justify the tips, if that applies, before you figure in the charges.
x'ing out and z'ing out aren't the same thing. you should x out at the end of a shift, if you run a tape for the whole day, or to take a quick reading. z'ing out should only be done at the end of the day, as it should return the total to zero.
if you're interested, i'll see if i can dig up the excel form that i developed a few years ago as a daily cash management sheet. whoever runs the register should fill it out completely every day and then attach the journal tape to it.
are you under or over on the count, Raine? and who's running the register? if you're always under in the drawer, you may have to look at the possibility that someone has sticky fingers. of course, if you're always over, the same thing might apply; someone's not ringing in all the sales, but isn't able to lift the correct amount. that's a real talent.
if you're the one who runs the register, be more careful making change and ringing in sales. and recheck your math. i used to go through this at the end of an 18-hour day, and it often took me a few tries to count the money accurately and to do the math right.
a big help is to have a constant bank. every day, every shift, the cashier should have the same amount of money in the till. that takes some doing unless you have big banks with enough change, but i think it's critical.
if you have cashiers, another old trick is to slip, say, $40 into the drawer when they're taking a break, and see if it shows up in the works.