so you mean decaying a sample on a pad?... if so...
1. shift-6
2. params
3. on the left side is decay... the default value is 5... increase it for a more gradual decay....

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for me its important to be organized....
in bank A..
i always have the kick on A13, snare on A14, hat on A15...
^thats basic so i get my creative juices pumping... depending on how ill the sample is i'll have the same kick snare.. and hat on the pads right under those... with slightly different filter settings... as far as the rest of the pads on bank A, like pad A16,A12, and those 8 others... ...those would be for my percussions...and extra drums... like a tom... rims.... tambourine...guiro, shaker,,,etc...
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basically bank a is for drums and percussions only.... its like that on every beat....


bank b is for samples and extra effects......i love to chop my samples... its organized based on the chops.... if its chopped into 4 equal pieces... then the 1st pads on the 1st row are filled... as far naming the samples... iam nit-picky and i have those organized too.... example... the name of the beat is dreamstar... so the melody samples are named DMSTARM1, DMSTARM2,etc.... the m denotes... melody.... for vocal samples... its like DMSTARV1, the v denotes vocal of course....
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iam giving you more info than you should know... but it helps in the long run....when you get creatively tired of a beat and you want to come back to it later....
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i should start my own mpc training lessons... you must provide your own hotel, food accomadations though...lol