To help save money on a student loan, the best option from your list would be to agree to automatic payments. Many lenders offer a discount on your interest rate for setting up automatic payments, which can save you money over the life of the loan.
The other options, such as finding a loan with a higher APR or taking a longer-term loan, would typically lead to higher costs over time, not savings. Making your payments on the first day of every month generally does not directly save money but is a good practice for avoiding late fees and managing your payments effectively.