Here are the possible solutions for one way to begin clue
Answer
Clue
Relevancy
anew
Clue
One way to begin
Definition
afresh, again
afresh
Clue
Way to begin
Definition
anew
shadowboxes
Clue
Trains, in a way, and the key to 18 of this puzzle's black squares. (Ones that begin with the keyword are asterisked. The others are for you to discover.)