I came across 7 nuggets about the topic : missed-puzzles on internet.
You can search these links on my public listing page on learning paths
Identify who is defending the prime pieces. King, Queen, Rook and bishop in that order
when giving a check whatever is the line of escape for the king you piece should make use of it if it can attack in that line
Puzzle Rating (#1076670) - sacrifice your blocker(hidden attack) during a sequence of checks