Couponing Lesson

I have been couponing for a while now and for the most part know what I'm doing.  Or at least I think I do.  Once and a while I just make mistakes.  Although they are few and far between, I make them. *wink*  I just wanted to share/ramble about my shopping experience yesterday.  So I planned out a trip to Target, I didn't give myself a estimated total for this trip (mistake) because I knew there were going to be a few things I may not get.  As well as some unconfirmed deals I was after. This estimated total is always nice to have when you are at the register.  I normally give myself a breakdown of what my coupon total would be as well.  After getting most of what was on my list and some, when I went to check out, I didn't pay any attention to the register I was going to. (mistake)  I  realized when it was to late of course.  I always watch the register like a hawk.  I was sure I didn't see her scan toothpaste.  I asked, she said she did and went on.  Then when scanning coupons, I thought some didn't scan, I asked, she says they took. 
End result:  I paid $57.92   according to my receipt I saved $28
Big plus:  I did get the 2 - $5 gift cards I was due back
Something wasn't right, I obviously didn't do a good job this trip.  Since I had the family with me, I couldn't figure this out until I got home.  On the way home I'm discussing this with my hubby.  First thing he says to me, "why did you go to that cashier?"  (This guy could concentrate on anything under any circumstance.  He's secretly a monk.  Just kidding.) 
I found that I was not charged for three items.  This cashier just wasn't paying attention.  She didn't scan the toothpaste. (My coupon was going to make it free)  And no, some coupons didn't scan.  Not being charged for items can sound nice but in the end it will mess up your transaction and just isn't the right thing to do.  During this trip I found some things on clearance that I didn't have coupons for so I did expect to pay a bit more.  It wasn't to far off though.
Paid: $57.92
Should have paid: $49.23
This mistake cost me: $8.69  (Not that bad)
Plus I did get my $10 in gift cards

Lesson:
Always have an idea of how much you are going to spend.
Know how many coupons you have and what they total.
Keep a running tally throughout the store (even if it's just in your head) this way you know what to expect.
Always profile your cashier.
Pay attention to your cashier very carefully they make mistakes too.   Their computers more so.