While on DoW, fatigue is really nothig to worry about. As stated previously in this thread, just power through it, 10/20% less SP per mob is still way more than 0% gained while waiting for it to reset.
DoH is a different story, those percentage points add up to a considerable amount of wasted resources while grinding. Either switch to a different craft when you hit yellow, or just take a crafting break period, unless of course you are grinding a cheap recipe, then sometimes powering though isn't really a big deal.
DoL fatigue is different as well, you'll hit "gathering" fatigue before actual fatigue.
This is where you've hit an invisible quota of items gathered, and your success will bottom out. You'll end up running from point to point with very little results (or in the case of fishing, either hooking nothing, or losing 75-85% of anything you do hook), resulting in a huge waste of time, unless you are into honing your marathon ability or you're really into losing lures for no good reason ...
Edited, Jul 13th 2011 4:52pm by Restyoneck
"Don't take it personally man, white knights would eat a can of **** if the label said SE on it. If anyone dared mention that it was not a good product, they'd just argue if someone can't appreciate the subtle nuances in the ****, they should just go back to eating lolrealfood, cuz the devs prolly know more about canning food than they do."