Definitely don't stress.

I don't use the Aus Post satchels as I use my own plain white satchels which are a better size for my items. I just write the address and then my PO generates a parcel label for $8.95 which has the tracking number. I enter the number manually into the order when I get home and finished.

The only thing I did tidy up recently were my postage policies. I had about 20 different ones which had accumulated over the years due to the different things I've sold. I went through everything in those policies and trimmed them right down to be consistent with what Ebay wants.