In Texas, the Homestead Exemption is a beautiful thing - - - besides a general discount to the bottom line of what you owe the county at year's end, it also caps the rate at which your tax-appraisal district can increase your home's taxable value.
It's a one-page form, and you don't need a third party firm to help you file. Just fill it out and mail to the Travis County tax assessor (if your home lies within Travis County boundaries. See me for help if you live in another county.)
Download it here:
http://www.traviscountytax.org/pdfs/070716ExForm.pdf