To better understand how casual drinkers can improve their coffee, two London professionals offered their advice. Joel McMillan runs Hasbeans Coffee, where he roasts beans daily, and Andres works behind the bar at Locomotive Espresso. McMillan, who has spent years roasting coffee, said many beginners get caught up in terminology that can be confusing. Andres, who prepares coffee daily for customers at Locomotive, echoed McMillan’s emphasis on freshness. “The best coffee is diner drip coffee that you don’t fuss over, that is barely measured,” he said.