build a better mousetrap

an ounce of prevention is better than a pound of cure

Precaution and prevention of an undesirable thing is preferable to dealing with its potential consequences.

better angels

Morally upright or otherwise positive attributes of human character.

better for it

In a more favorable position on the whole due to something, despite possible drawbacks.

better luck next time

Used to wish somebody hope in future success after a failure.

better nature

the more amiable qualities of someone

better place

Heaven; happiness after death.

better than sex

Superlative; wonderful.

build a case

to compile evidence that supports a charge against someone.