Say "Jai Shri Ram" or "Har Har Mahadev" before buying anything from anyone just to ensure that they are Hindus, if they a Muxlims they won't say it back.

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Besides that, you can also check for swastikas, ॐ made from roli or kumkum, chunris, red threads, stickers, pictures or any idols of gods on thelas or small shops because Hindus mostly DO have any one of those.

To people who think it's not okay to judge everyone, well now I will because I've seen enough. You can't keep respecting them wearing the mask of secularism while they look down upon you and destroy your culture right in front of your eyes. Jai Shri Ram!