I usually copy everything inside:

Wow/wtf/account/accountname

Except for the realms where toon data is stocked.

I copy it to the desired target accountname

I log the toons I want to copy to.
I log off and delete all except their name dir (I think you can just create this dir and skip this process though).

I go to:

Wow/wtf/account/accountname/maintoonname

Copy everything inside.

Paste it at:

Wow/wtf/account/accountname/alttoonname

It works at almost 100%. I use Macaroon now and everything is much easier.

Hope I could help.