In 2022, cash/check donations are limited to 60% of your adjusted gross income [AGI]. Non-cash [property] donations are limited to 50% of your AGI. Donations that you make, but are prevented from deducting (because you've donated more than 60/50% of your AGI), are rolled over to the next year.
The next question is "how do I value my donations?". The easy answer is "what are other people paying for similar items?". EBay, Amazon, and Kelly Blue Book are good starting points.
Donations must be given to non-profit organizations, which can include churches, schools, hospitals, towns, states, etc. [This excludes many GoFundMe fundraisers.]
Every donation must have a corresponding receipt. For noncash contributions worth over $500 (tangible or intangible property), you must attach form 8283 to your return, which just requires some details of the property. For noncash contributions worth over $5,000, you must attach form 8283 and must obtain a qualified appraisal of the item donated.