Best chances of getting merit is probably to give an informative answer on a question someone asks, ( Beginners & Help, Technical Support, etc.) within the first few replies..
And here is the problem (especially Beginners & Help).
The people asking questions there are in general very new to this domain and also very new to the forum itself.
Most of them are creating a new account just to ask their questions and they almost never log back in.
Since their accounts are new they don't have any merit points, so they cannot give any merit points, even if they would know how (and that's another issue).
That's what the merit sources are for. They just browse sections like these for good answers/good posts as i stated above.
You'd essentially cater them, instead of the OP in said thread (Although i'm pretty sure you're ultimately also helping the OP with a good answer.).