When I work from home, I tend to get sit down at the computer and get started right away, like two hours before I would normally be at my desk. A few hours into my day, when my pits start feeling clammy and I realize there's still sleep-crud around my eyes I realize that I've left some things undone. Some hygiene things.
Tip For You: When working from home, remember to treat yourself like the fully integrated member of society that you are. Brush your teeth! Wash your face! If you're feeling energetic, maybe even take a shower (confession: yesterday I didn't bathe [I always take a bath] until 4 pm and so after I washed my face, went straight to night cream, bypassing my daytime moisturizing routine entirely; it felt creepy) .
Doing these little things will make everything so much easier when you pop out to the local cafe at 1 pm for a cookie or to Taco Bell for a taco if you're already moderately presentable.