"popular practice" is correct and usable in written English.
You can use it to refer to any practice, custom, or habit that is widely followed by many people. For example, "In popular practice, the bride's family is traditionally responsible for paying for the wedding."
Predicting his home run total has been a popular practice among Japanese reporters.
Finally, New Year's Eve in Honolulu is unremarkable but for the overwhelmingly popular practice of setting off firecrackers.
Mr. Vogt likened it to the once popular practice of using small mirrors to reflect the sun into people's eyes.
He imposed chastity on the priests, to their distress; he forbade incest, apparently a popular practice among the people.
The organ mass, in which the choir and the organ alternated lines of the liturgical text, was a popular practice.
Setting up such accounts has become a popular practice among a number of financial institutions that provide services to affluent individuals.
According to Marcy Magiera, editor of Video Business, a trade publication, rental by mail is by no means a popular practice in the industry.
Back in 1996 a man named Phil Quick won a settlement from a muffler production plant in Grinnell, Iowa, where bagging was a popular practice.
A popular practice for hillwalkers is to "bag a munro", the aim being to "collect" the whole lot – easier said than done given the Scottish weather.
The decision today did not explicitly address graduation ceremonies, but the majority's analysis cast serious doubt on the increasingly popular practice of student-led graduation prayers.
So has the increasingly popular practice of packaging mortgages into bonds that are then sold to many investors, thus spreading the risk of default.
