You can’t simply tell the state, county, or municipality how much you think your home is worth and let them take it from there. Your home’s value for tax purposes is based on its appraised value, and the appraiser is not an independent third party. Tax assessors typically work for the government.
Most states have an appeal process in place, so you have some recourse if you receive an astronomical and unreasonable assessment.
You can expect your tax bill to go up if you add a second floor to your home or put an in-ground swimming pool in your backyard because improvements such as these will most likely increase your home’s value. You could find yourself paying more in property taxes even if your state’s tax rate remains unchanged because that percentage rate is applied to a larger value.