For me, I think it was just repeatedly starting and stopping, and realizing that I eat much better when I track. Also, I used Lose It at the time I really got serious about tracking, and I think that helped. I found it to be really intuitive and easy to use, much more than My Fitness Pal or other trackers I've tried.
Go for progress, not perfection. If you forget to track breakfast, and can't remember what you ate, just start w/lunch. If you forget to measure, use your best estimate. It's good to measure/weigh at first so you know you're getting the portions right, but once you've done it a bit you can probably skip that step (I do), which makes it simpler.
Also, I mostly have the same thing for breakfast every day, and similar things for lunch - which makes portions and tracking easier.