Fingerspelling use varies hugely between signers, some people use it a lot and some use it much less. However, it is used for many different parts o the language in different ways, including for:
Whole names of people where someone does not know the name sign (eg b-i-l-l-s-t-o-k-o-e- or d-o-r-o-t-h-y-m-i-l-e-s)
Whole other content words (e-c-l-i-p-s-e or i-r-a-q)