I believe my value is already low or the appraisal district decrased my value this year. Should I still protest?

YES!  The appraisal district in unable to individually look at each home when determining the proposed market value each year.  Often times your home is appraised above the median of other similar homes & a property tax appeal is warranted.  NTPTS looks at the specific factors unique to your home when preparing a tax protest.  Unequal appeals are often a basis for a reduction in property taxes.