My problem has more to do with discipline. I try to be careful but
somehow let myself down. I would appreciate any tips given which can
help.

I have a worksheet that includes product and quantities in the row. It
works well does what I want it to do but no matter how much care I
think I am taking, everynow and then I find that the 'quantity' column
only has moved up or down. So where I was reporting 23 instances of
something the column says I have another amount, and the other columns
are cocked up. I hope I explained this well enough.

I have to alphabetise the lists every now and then and I think I am
checking and double checking but obviously at that point something
goes wrong.

I am constantly being surprised how this excellent program helps you
cope with things going wrong. Has anyone any ideas or wrinkles which
may help me.