EXS 24 Logic Sampler Users Group

I've only recently started to make my own samples instead of using 
libraries, doing it the old-fashioned way with microphone(s) and 
portable dat recorder and lots of gaffers tape.

I've got a question about editing one-shots, specifically drum shots, 
but any one-shot sample:

Is there a standard way to edit "around" a one-shot?  Do you trim the 
beginning of the sample right up to the beginning of the sound, or is 
there a standard amount of "leader" that's left before the sound,

Clearly this question shows the massive holes in my understanding of 
digital music, but I'd like to know how you more experienced 
recordists do it. Is there a rule-of-thumb for trimming the sample, 
and rule for where you place the "anchor" or whatever you call the 
marker that tells the sampler where to begin relative to the actual 
onset of the sound?

I'm on the road and only able to get connected to news servers 
occasionaly, If you could respond directly, thank you,

Nittacci