The thing I wish I had done was start using up my food stocks sooner - the few weeks before we left we went to so many family and friends gatherings, we didn't use as much food at home as we thought, I ended up giving loads of dry goods away.
Also have a look on the SA immigration website if you are unsure about any items of doubt for the container. We had three items confiscated - a strimmer which hadn't been cleaned (Nick's fault!), a Xmas decoration made of twigs and an old snakeskin handbag. So they do go through things thoroughly as we had around 60 packing boxes which must have been checked. Actually after we got here, at my induction day at TAFE we had a talk from immigration about things you can and can't send into the country, and it was really useful but too late for us by then!
Also don't go with the cheapest shipping agent, we were disappointed with the one we chose and became uneasy with them before we left but by then it was too late to change our minds. We are still unpacking our boxes at the moment and have found quite a few broken items so far. I will be posting a thread when we have finished unpacking everything to let everyone know who they are, but in the meantime if there is anyone coming from the Bristol area, PM me and I will give you their name to avoid!
Basically go with your gut instincts.
Good luck with the lists!