That the point how merits come to us:
So try your best to make your posts useful and helpful to others.
I collect a bit merits so far (21) since merits system exists. But most of my received merits come from my post on the technical board (Altcoin [mining]) that the most mastered by me. You will felt "hard to get merits" while you want to receive it.
Just forget about merits (merits is nothing) and keep posting on the things that you mastered the most, keep spread positive things, be useful and merits will come to you.