This may sound like a bit of rant, but i believe some cats can use and agree with what i've jotted below......skip if you illiterate or just don't like reading
hmm i know this technique i've used it a few times myself (not saying im a master or anything), i actually started doing this on accident when i was working on my bassline filtering, it's a bit hard for me to do it in FL due to only being able to tap one sample at a time, unlike the mp which u can address different samples to different keys, but in fl for me it's possible, just not easy as i'd want it to be.
It isn't that hard to understand with experience, i truly believe it's your ear and how you "hear" music that gets this job done, i think everyone can agree that.....as you become more experienced in sampling and beatmaking, how you hear music will begin to change, and how EVERYONE HEAR'S MUSIC IS DIFFERENT.
When i say change, i mean "CHANGE" not hearing a obvious sample like earth,wind,and fire "love holiday" and going "oh thats a tight azz soul sample, i know i can make something out of that!" or doing a loop out of the obvious.
Nah, i mean hearing something you'd never expect or don't like and already hearing what it sounds like pitched up and down before you even pitch it up and down, to see if you can use it to make something. Or when you hear it you've already took parts of what you've heard and started constructing a beat out of it in ur head And even doing that with what i've said earlier about the whole pre-hearing pitch thing, hence thats why some people be "humming" tunes out when they makin beats.
Take all that and apply it to 2 or more samples and your basically manipulating sounds and constructing them to how YOU want YOUR beat to sound like in your head, the next question is, can you use what you have to make ur construction a reality?. Ya gotta be precise though.
snizzy's 2 cents, hope it helps someone, i know it sounds crazy and all, but that's one of the ways my brain processes when im makin joints.