You're pretty close. They have their ideas, spend days just doing bass sampling etc and then when it comes to actually putting a tune together it works alot easier. Hence why alot of their music sounds so clean. If a sound doesn't quite fit in there, get rid of it so the other parts of the track can breathe. Don't put a stab or woosh effect for the sake of it.
I can definately see why they do it though, cause you can sit there for hours just looking for that one sound that you may never actually find, there for stagnating the production process.
Yup, Create your sounds before hand, which requires knowledge of how to create that sound. It takes an ENTIRE whole process.
Get your first base sound
then add ohmicide
Then add maybe a sugabytes WOW
Add some more effects
Add more effects
Youre done. Thats JUST an example though you can do whatever the hell you want with sound! Everything does something a bit differently! For example a saturator VST brings it all together more, saturates it more, where as an echo just echos off the signal... So you see it all plays with the same frequenc but does something different! So play with it and get a feel for it! There is no guideline other then Calyx and Teebee probably know their sound synthesis REALLY WELL and sit there and really know what they are doing. Its about knowing what you are doing! And to know you got to learn! And to learn you got to practice! So practice and learn well my friend!