I focus on one day at a time. Making better food choices, pushing myself to exercise (cardio) and committing to strength training by scheduling appointments with a Personal Trainer. Focusing on changing one day at a time. I did not get this way (overweight) overnight and the changes I want to see will also not happen overnight.
You will slip up - you will make bad choices every once in a while. Focus on the big picture - and do not let these occasional slip ups derail your progress!