I recently finished losing about 40 pounds, or around 3 stone as the British would say. The main technique I used was a calorie-counter app on my iPhone called myFitnessPal. It’s a simple concept: you just type in every single thing you eat, every day, every meal. It helped me immensely because I tend to “graze” all day. I never keep track of my eating. I just keep telling myself I can just have some more. I slide down the slippery food slope all day.