Are there good innovations and bad innovations, and good practices and bad practices?

The term "Sunnah" has two applications: a Shariah (legal/religious) one and a linguistic one. In its Shariah sense, there is absolutely nothing bad in it, as it refers to the sayings, actions, and approvals of the Prophet, peace be upon him. As for its linguistic meaning, there is good and bad within it, and its meaning is "way" or "practice," as in the Hadith: "Whoever introduces a good Sunnah (practice/way) in Islam will have its reward... and whoever introduces a bad Sunnah (practice/way) in Islam will bear its burden..."