I got my Toby at 7 weeks and the breeder had his ears taped with masking tape to help them along. He is now 14 weeks and we havent had to replace the tape for about a week now

! and believe me my baby has some big ears I thought they would never stand.
SO..
There are probably some people that dont agree with doing this but it worked for us and it didnt hurt Toby at all. Also I asked my vet if I was doing all this properly and he said I was just fine.
What we did was every 2-3 dayswe would take off the tape (standard 1inch 3M masking tape). He would have a bit of wax built up so i would clean the easy to get to parts with a cotton ball and alochol (i used q-tips for the crevises). Then we make sure all of the sticky is out of his hair. Usually we would let them air out for a while (sometimes overnight) Then we would use like 2 2-3 inch peices to retape. Just make sure you trim any excess hair and you crease the ear well. The tape should be tight enough so they stand (they look like little horns) but not so tight they cut off circulation.
Dont give up though they have good days and bad days! I know the book"yorkies for dummies" says to keep trying until around 6 months!
Hope this was helpful!!