There are many ways to easily spot it:
1) Please answer comments
2) "Let, " (note the comma)
3) Bolding/blockquoting questions
4) "My attempt(s)-" or "Attempt(s):"
5) Almost always uses complex-analysis tag
6) Uses 5 tags (maximum) before edited out by users **(no longer the case)**
7) Multiple insubstantial edits (asking for feedback)
8) One-word username