I use sample packs (one-shots, loops, fx) all the time. I don't keep as many as I used to though. I've got several kits I use on a regular basis. I've noticed alot of different packs have duplicated samples. Like, I've found the exact same kicks and snares in three or four different kits, just renamed a bit different.
Some good ones I always use is the Alchemist kit, 9th Wonder, Superslikuzi's kit, Warbeats vol. 2 and Kataklysm. Also use packs from PrimeLoops, Vengeance and Sounds in HD. I've only been making beats for a couple of years, so I'm not too great at creating my own sounds, although I have been layering and EQing alot of stuff then saving those into my own custom-made folder.
Often I'll sequence out a loop in FL, then layer a drumloop from a kit under it in the playlist then lower the volume of it. Adds something more to my drums. FLStudio makes it easy to match tempos and whatnot.
Shoyarite - SouthernFriedProductions - Soundcloud