Good work – I really like your first and third headlines. The second one is a little generic – it doesn’t quite arouse curiosity.
Is the Habit of Expectation Killing your Marriage?
=> This is a great headline. It’s really specific. Well done.
A Simple Action to make your Marriage Smooth Sailing (and Avoid Bitterness in your Relationship)
=> The first part is a little generic, but this doesn’t matter as the second part makes this specific again, and bitterness is a good power word. Perhaps shorten slightly as at nearly 100 characters it’s quite long:
How to Make Your Marriage Smooth Sailing (And Avoid Bitterness in Your Relationship)
Enchant readers. Woo customers. Win business.