Now that you have recorded and edited your sample, the fun can begin. The first thing you'll want to do is map your sample to the keyboard, a process usually called - you guessed it - keymapping. You may notice that stretching a sample across the whole keyboard sounds pretty goofy, which can be cool. However, if you want your sounds to be realistic, you'll have to record the same sound at many different pitches, creating a "multisample." As you can imagine, playing a different sample every octave will sound good, and every 5th will sound even better, and so on. Some instruments will require more samples than others to sound realistic, but be careful not to go overboard.
If you want to sound even more realistic, you could record different dynamics of the sound you are sampling. This process, called velocity switching, triggers different samples based on the velocity value of the midi signal triggering it. However, this concept is more difficult, and will not be discussed further in this article. It's just good for you to know that it exists.
Now that you have your basic sound, you can begin to manipulate it; there really are endless possibilities. For example, you could take a guitar sound, and pass it through a low pass filter with a cutoff at around 800 Hz. Then on another track, you could take the same sample and put it through a resonant high pass filter at around 2500 Hz. Maybe apply a bit of a flanger effect to the second sample, and you now have a unique sound.
What if you played the sample in reverse? Many soft samplers now come with built-in effects, which usually require much less processor power than using a dedicated plugin for that effect. Feeling lo-fi? You could resample your new creation at a lower sample rate and bit depth. How would it sound at 22 KHz / 8 bit? The only way to find out is experiment, so get to it!
"Looking at a sampler the way it was used first - to try to simulate real instruments - you didn't have to get a session guitarist and you could just be like, 'Hey, I can have an orchestra in my track, and I can have a guitar, and it sounds real!' And I think that's the wrong way to use sampling.
The right way is to get the guitar, and go, 'Right, that's a guitar. Let's make it into something that a guitar could never possibly be.' Take it away from the source and try to make it something else. Might as well just get a bloody guitarist if you want a guitarist. There's plenty of them." - Amon Tobin
This quote speaks volumes. Although sampling can be a practical way to incorporate an ordinary element like drums or a bass line into your composition, it can also be a versatile tool for exploring new sonic horizons. Have fun - and don't get sued.