do you have an automated method of doing the filtering or is this all manual

The sorting is automated.

  word_count = Counter(w for s in sentences for w in words(s))

  sentences_by_word = defaultdict(list)
  for s in sentences:
    for w in words(s):
      sentences_by_word[w].append(s)

  sentence_sort_key = lambda s: sorted(word_count[w] for w in set(words(s)))

  for w, _ in word_count.most_common():
    candidates = sorted(sentences_by_word[w], key=sentence_sort_key, reverse=True)[:5]
    for c in candidates:
      print(w, ':', c)
    input()

The final step of choosing one sentence and turning it into an Anki flashcard is manual.