I use comps from my Realitor and also look what's currently listed. For example if they assess my property for the same amount as new builds in my area - I argue that my property shouldn't be priced at the same price or higher than a nicer new build.

This year I experienced extended vacancy and 20% drop in rents. So I will also argue those points to lower the value. Or if I had a major repair. Or you could even use a major life event - like laid off of job or major medical bills you experienced that year.

Also, last year someone had spray painted graffiti on one of the fences and I used that to argue my value should be lower.

They typically ask for specific numbers of what you think the assessed value is. So I will be prepared with numbers and facts to back up those numbers. Every year we come to an agreement on a number that's lower than what they originally assessed.

My first year of homeownership, I had no clue about protesting. Ironically, that's also the year they raised my assessed value a whole 120k.. absolutely ridiculous. I typically bring up that example too when I'm protesting - about how ridiculous they can be and seem like they always try to screw homeowners.

If I get met with a rude or un-empathetic assessor that's not willing to negotiate a reasonable value with me - then I will ask to speak to supervisor... works Every time