Local secondhand store owners say that’s due to a number of factors. “Consumer tastes have kind of changed,” said Rob Singh, one half of the team behind the Found Boston and Fenway Flea vintage markets. Hanadi Hamzeh, founder of Covet Boston, agrees that buyers see secondhand shopping as an environmentally friendly option. But she also believes thrifting is a bit more fun than shopping online or in a classic retail store. That’s why I asked Hamzeh and Singh to share a few of their expert tips for shopping secondhand.