Apart from the names of works (especially if they are not in the title of the article, etc: and preferably, if originally in Russian, in the form Mashen'ka/Mary or Dar/The Gift), and writers who matter to Nabokov (Shakespeare, Pushkin, Khodasevich, Joyce, etc) and others of close biographical interest (Nabokov, Véra; Nabokov, Dmitri; Wilson, Edmund, etc) some of the more useful tags include:
adaptation
aesthetics
America
annotation
art
autobiography
Berlin
Bibliographical matters
Biographical matters
biography as subject
biography of VN
chess
class, social
classical literature
criticism
democracy
design
detail
dreams
England
emigration
epistemology
essays
ethics
evolution
exile
fate
film
France
freedom
French literature
gender
genre
geography
history
humor
imagery
imagination
indeterminism
influence of VN
influence on VN
interviews
language
Lepidoptera
letters
literary theory
memory
metaphysics
mimicry
modernism
narrative
pattern
plays
poetry
politics
popular culture
psychology
reader
realism
reception
Russia
Russian literature
science
sex
sources
space
stories
style
synesthesia
teaching
texts and editions
time
translation
women