Open and HSA (Health Savings Account), you can deduct from your gross income what you put in the account. You use the HSA money for medical costs so it's as if you are never taxed on anything medical (glasses, chiro, medicine...).
Open an IRA (Individual Retirement Account), you can deduct all that too.
In some cases, school expenses can be deductible.
My friend works as an Emergency Medical Technician and he can deduct all his uniform costs which comes out to be a lot for shoes, underwear, haircuts, shirts, dry cleaning, etc.
Getting your 'gross' income low is the key.
If you rent, take the deduction for renters.
It's probably worth it to buy a tax prep program which can guide you through all the steps. Sometimes you can use one for free at the library.