There is no such thing as fastest way to earn merit.
Correct. There is no instant way or a shortcut way to earn merits.
It must take time for learning everything first. In this way, we can get enough knowledge and experience. This will always be the basis for a quality post.
it really depends on you and your knowledge that you have. It depends on the post that you post. Post that must be informative to others. Other who really finds your posts helpful and informative will give you merits.
Of course, knowledge and our contribution to the forum will be the reason to get merits. When we help other people, they may appreciate our contribution with merits. And when we make quality posts, it is also a reason for people to give merits.
The merit will come when it has to come and where from it has to come. Just keep up the hard work and it will pay you someday.
When we deserve for merits, people will reward us with merits. In most cases, it will very depend on how useful our posts and how good its quality. Sure, never give up to improve your post quality and your contribution in this forum. Someday, there should be merits to earn when your posts deserve it.