I hope I could give you some hints for a start. I certainly have quite a lot to learn from you. That takes training, and they did not learn this in school. But slowly, if they write signs more and more, that changes. In other words, this is a process and a complex one.
Writing is different from signing.
Speaking and signing are preprogrammed and emerge naturally, given a community of native speakers and signers. These findings tend to be robust and are quite well established in the majority of spoken languages. I think that something very similar to the phonological awareness training could be done with respect to sign language using SignWriting. That seems to be promising research. The crew at the Neuropsycholinguistics Laboratory at the University of Sao Paulo.