When you lack faith in the shooter
You don't always need to bet the shooter will make their Point. You can bet that it won't happen.
The Don't Pass is the opposite of the Pass Line. Where one wins, the other loses.
Lay Odds are an extra bet you can add to your Don't Pass that gets paid True Odds.
Don't Comes are just like mini Don't Pass bets. It's always betting against the next Point number to roll.
Just like the Don't Pass, you can add Lay Odds to your Don't Come bet which gets paid True Odds.
If you can make a proper Overlay, vig and all, I'd say you've learned how to play Craps.