Clue: Stone doing his usual thing walking along (9)
Answer: STROLLING
Explanation: Definition: walking along

**St**. (stone) + **ROLLING** ("doing his usual thing", i.e. a rolling stone, as in the band or the proverb)
 

 
*You could argue that most stones don't roll very often, so "rolling" is not "their usual thing". They tend to just stay in one place most of the time, until disturbed.