I know my dad used to order them, with the name embroidered, from those little home shopping magazines. Alternatively you can buy a small roll of tape from Woolies which you write the name with biro and then iron onto the item, i have used that before and it seems to work!
I forgot to mention that a money saving tip I was given was to just have your surname put on the tapes. Or if you have the same sex kids place all on the same tape and fold the unwanted name in the tape so the wanted bit shows eg Lizzie Molly Posy Smith, order the 144 and tuck Molly and Posy to read Lizzy Smith and so on.. My kids are mixed so I had the girls names put on first and the initial of my sons first name next to our surname so Lizzy Posy M. Smith. Saved keeping track of three lots of tags too!