When I'm logging my food and have a higher calorie day than expected I look back for the average of the week that puts it in perspective.
Me personally, I go one day at a time, sometimes I can string 3-4 days together when I have done my best in exercise and nutrition. I figure it's all in the practice. I eventually will become unconciously competent instead of my current conciously competent.
Highest weight October 1st, 2011 247.6
Starting weight January 3rd, 2012 227.8
January pounds lost 7.8 = 220
February pounds lost 4.4 = 215.6
March pounds lost 2.6 = 213 (do better in April)
Goal weight 160.4