Pennies: Currently, it cost 2.41 cents to create our 1 cent piece. If the penny was useful for something, this would be no problem. However, it is extremely impractical to use them in financial transactions; some of which, like vending machines or car meters, don't even allow the use of pennies. Stopping penny production would save around $60M each year, helping some budget concerns.
Nickles: Currently, it cost more than 11 cents to create our 5 cent piece. Since nickles are somewhat used, we should reduce the amount the Mint creates (75%).
Dollar Bill: Currently our country has both $1 bills and coins. With cotton costs rising, we need to focus on using the $1 coins over the bill and phase the bill out over a 5 year period.
End penny production, and reduce nickle and $1 bill production.