Pay yourself first.The easiest way to save money rather than spending it is to make sure that that you never get a chance to spend the money in the first place. Arranging for a portion of each paycheck to be deposited directly into a savings account or a retirement account takes the stress and tedium out of the process of deciding how much money to save and how much to keep for yourself each month — basically, you save automatically and the money you keep each month is yours to spend as you please. Over time, depositing even a small portion of each paycheck into your savings can add up (especially when you take interest into account) so start as soon as you can for maximum benefit.
To set up an automatic deposit, talk to the payroll staff at your job (or, if your employer uses one, your third-party payroll service). If you can provide account information for a savings account separate from your basic checking account, you should generally be able to set up a direct deposit scheme with no problems.
If for some reason you can't set up an automatic deposit for each paycheck (like if you support yourself with freelance work or are paid mostly in cash), decide on a specific cash amount to manually deposit into a savings account each month and stick to this goal.