I often try to see whether a product is reviewed on YouTube, a lot harder to fake a video review. For services such as movers, doctor’s, etc. I often use the reviews on Google maps. Word of mouth is probably best of all though.
Some general advice:
If you’re buying a product always buy via a credit card as you have greater protections and can always issue a chargeback if all else fails. Also, if you’re a victim of fraud and your credit card gets maxed you will still be able to make rent / mortgage payments as your checking / current account won’t have been exposed - plus credit card companies are motivated to help as they are the ones liable for the transactions.
For services, insist on payment after delivery. That way the provider is more motivated to provide a good service so they get paid and recoup their costs, and if it goes tits up you can withhold payment rather than having to try and get a refund.
If you can’t afford a reasonable worst case scenario, get insurance.