There is a degree of talent involved but basically knowing how to put it altogether, listening to feeback and just overall man, making a lot of beats finding what you like and doing it sort of like a chef would do when they make excellent dishes without any cookbook they just know from doing and experimenting with tastebuds, we do that with our own and other peoples ears, most cats on here i betcha gotta slew of joints they don made, now whether we ever gonna hear em i doubt it..
To tell you the truth even before coming here i got at least 15 or 20 spindles of the 50 cd packs each cd completely full with beats and loads more thats either been deleted accidently lost on hard drives over the years, i been making beats for crews, emcees, mixtapes or whatever since 2000 or before man, you just gotta hava lot of time on your hands and passion, keep making tracks, listen to other beats, find out the elements that make up a hot beat...get a library of a lot of dope instrumentals already used by the major artists study them...
A lot of my beatmaking came straight as a result of having artists to work with and they go hey can you take that out, can you put this in, that sound need to come down, or use a different snare etc..or they have an instrumental either from another producer or a mixtape instrumental and they want you to make a similiar beat..(this is where jacking comes into play when an emcee has a cd and there is this beat that is halfway done, he asks you to redo it, it really is not that you intended to jack but in order to fulfill what the emcee or artist wants this happens)....its not an overnight thing though so dont think cause you got the means you gonna produce top quality off the jump, it wont happen, you have to work at this craft....one way to always look at it is like this...i want to paint a picture, what colors will be needed and what will the picture look like when beginning, but when you actually compose that joint, its just like writing a composition in english class...you gotta follow a formula, the intro, the thesis or main point, then you reinforce that by coming up with things that keep establishing the main point then you sum it all up and after you made the point you close.
liken the hook to the thesis statement, you gonna use a melody to back it up, then you gonna continuously hear that element of the melody through the entire song but possibly less volume or using other instruments...while it plays through 16 bars of the chorus...you need to go study some composition theory and music theory but if you not composing from scratch....the music theory is good to have but not as important if you not forming chords etc...