I’m not a tax accountant but I certainly pay taxes like they are going out of style. 
Do your own diligence, and use the IRS site.
There are two “$500” levels to be concerned about.
$500 is the trigger level for filing an 8283 so if you stay under $500 then the donation can just be a line item on your 1040. No big deal to go over the $500 limit; it just requires a form.
The second $500 level is that a single item with a value of $500 requires an appraisal (this is a new rule):
*http://www.irs.gov/newsroom/article/0,,id=164997,00.html
Rules for Clothing and Household Items
To be deductible, clothing and household items donated to charity after Aug. 17, 2006, must be in good used condition or better. However, a taxpayer may claim a deduction of more than $500 for any single item, regardless of its condition, if the taxpayer includes a qualified appraisal of the item with the return. Household items include furniture, furnishings, electronics, appliances, and linens.*
Here are some specifics on how to value deductions: Publication 561 (01/2023), Determining the Value of Donated Property | Internal Revenue Service
Whether or not you file an 8283 you must keep records, and the rigor of these records falls into four categories: Under 250; 250-499, 500-4,999 and Over 5,000. Here are the rules for those records: http://www.irs.gov/pub/irs-pdf/p526.pdf p19
Never worry about audits unless you are committing tax fraud. If the IRS raises an eyebrow, you will get a simple polite request for more documentation about that one item. Where people get nervous is when they are pushing the evasion or fraud envelope all over the place. One red flag might then trigger a review of the whole return. It’s highly unlikely this applies to you b/c you would not be soliciting tax advice here if your tax bill were extraordinarily high–one of your peeps would be doing your taxes.