Routine
We are creatures of routine and habit. It makes us comfortable, happy, and predictable, and any break in that routine often results in some form of chaos. Therefore, translating that routine from office to home is a foundation of successful telework. Take a moment and think of every aspect of a typical daily routine - down to the smallest detail. Waking, bathing, dressing, breakfast, and so on. And how often do you deviate from that routine? More importantly, why should any of that change just because of where you are sitting for the next eight hours?
If your office is one of suits and ties, the suggestion here is certainly not one of pressed shirts and coordinated ensembles in your home. But falling into the routine of stank and pajamas does just that - it becomes a new routine that is in direct conflict with the original. Your approach to the work day is shaped by a great deal, and minimizing any changes to that will ease the transition to working from home. Therefore, take the time to adhere to regularity. Sure, without a commute to consider, perhaps another hour of sleep will not hurt. But if showering, eating breakfast, and reading the paper were part of your morning before, there is little reason to disrupt that.
It sounds silly, but soap and actual clothes will set the tone for the entire workday. It additionally touches on the issue of perception. Saying "I don’t care what people think," is nice, but if a spouse or roommate sees you taking a serious approach to the workday, there is less inclination to interrupt.