Okay, let's see if I could put this into words as far as "secret" is concerned and at the same time making it as easy to understand as possible. I don't think there is any particular secret to drawing or perfecting drawing. To me personally, drawing kinda came naturally. But to those who struggles in this field, the best advice I could probably offer is to really practice. I believe it really depends on what you like to draw and the amount of details involved.
Let's just assume you like to draw people in general (Marvel and DC comic book super heroes were my favorite to draw growing up) and you just wanted to draw from the neck up, then it isn't too hard.
But if you want to focus on drawing from head to toe (involving more details and time) then it will definitely also involves more of looking at photos and pictures of people in different standing and posed positions.
Really study and look over every small details and if you have a photo-graphic memory, a big plus, it'll really help out alot when you are ready to put it in drawing....Same rules applies for everything else that you would like to draw.
Drawing people or individual character is much easier if you start with the head and work your way down, just as you would, when looking someone over in sight. Same goes for drawing trees, animals, and others that I can't think of at the moment. My point is that you must develope or maintain a vintage point in everything that you want to draw. And once you do, it'll become easier and easier.
What I used to do, if I plan to draw from looking at a picture, I would use a ruler and draw a square around whatever I wanted to draw, using the one inch mark on the ruler, I would mark from 1 through
whatever across (top and bottom) and then the same way down (both sides) After marking all the one inch mark, I would then proceed to draw straight lines, horizontally and vertically, to all the one inch mark across from each other. I did this to the picture first....after I finished, then I would draw the exact same square duplicating all lines I did with the picture unto a drawing paper...and thus, creating small individual squares within the big square on both picture and drawing paper.
The final stage would be to concentrate on each individual squares, however and whichever square to start at is entirely up to you, and draw just what's in that square. Proceed on to the next square and so on until you have finished and the final result would be an exact duplicate of the picture. When you finish, erase the lines and noone would ever know except you.....I only used this method because it was easier to concentrate one square at a time keeping everything well organized. Once you become good, through practice and such, then you won't need the squares any more......Good-luck and keep practicing because practice makes perfect.