Salsa music has significant amount of layering beyond the 8 beats. When you first start dancing, all you care about is staying on beat while executing patterns. However, in order to pass the lead's 2nd plateau, you must be able to design you combos based on the music. The music in fact guides you to the type of patterns you should be executing during each measure. For the pros, they can hear it coming miles away and can improvise on the fly; that is why they always seem to do the "right" move at the right times.
Music is like water and good music does NOT flow consistently. Picture water running down a stream, it can
- hit the side bank and make a splash (break)
- the stream may change size, increasing or decreasing the flow (accent)
- hits a dead end and reverses the flow (counter)
As the above video suggests, breaks are good for sudden change in movements, ie. sharp turns, checks, posing. Accents are good for smoothness; if the flow is increasing, combos should reflect it by building momentum (NT360s, CC360s, follow LHTs into lead LHTs for gearing effect). Counter is a special type of break where you reverse the flow (ie, follow LHT + lead RHT).
Even though there have been better performers since Oliver Pineda, he is still the king of combo design on the social floor. That is why when you integrate your idol, you cannot just take out 1 or 2 moves, you have to mimic the entire flow; the build up is just as important as the special move that you are after. I would suggest going further during practice and use the same song as well, so you can feel the entire construct.