I just ran across this cool tutorial on PSDTUTS and thougt it had some awesome info about maximizing your efficency as a designer, and personally I feel non-destructive editing is key. If you are unfamiliar with non-destructive editing, in a nutshell it means not making permanent alterations or do damage to the original image file data placed or otherwise. This will in turn maximize the editability of the file for future revisions, alterations, etc..

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