As someone who has just started and facing the same uphill battle..

1) You want to give answers as thoroughly as possible, using very plain English, in a way that's easy to follow and isn't condescending..
2) Put thought and care into your responses.. make sure you quote who you are speaking to and answer the question to the best of your ability.
3) Don't just spam posts.. post on things only that you are knowledgeable about through experience or by trade, and avoid posting fluff posts.. this will not work.
4) Set goals and be reasonable... 1 merit per day is very reachable..I've been posting for 3 days and have gained 3 merit.. so I'm just taking it out piece by piece.
5) Know the system is an uphill battle but will work for you in the longrun.. the content that you read will be more worthwhile with less spam and fluff accounts.. which will lead to the bounties/banners and other perks to have less people bloating them lowering their value.

Good luck to all who read this, we'll all make it eventually