Just over 10 years ago I lost a huge amount of weight through Jenny Craig (50+ kilos). Sadly, I put it all back on again in the space of three years and developed gallstones, resulting in my gallbladder being removed. I also developed Coeliac disease which may or may not be related to all that. Long story short: be careful about losing a huge amount of weight too quickly.
I could not believe how differently people treated me when I was skinny - all of a sudden, life just became very easy - job offers, social invitations, smiles from strangers ... but I was miserable. As well as being freezing cold all the time, I was very hangry. I actually developed a bit of an eating disorder because I was too afraid to put weight on. At my lowest, I weighed just over 46kg and was a very scary size 6-8 (NZ sizing). I started working in a miserable job which led to emotional eating, which was my undoing.
Now I'm chubby, yet content. I'm about a size 12-14 (NZ sizing), so not huge, but I could definitely lose a bit of weight. I managed to get my weight back down to this level by pre-making all my meals (spending Sundays preparing for the week ahead), exercising very strict portion control, but eating a little bit of everything so I don't feel like I'm missing out on anything. I have these neat little containers that I bought from Kmart which have three sections, and I stick to filling the largest with vegetables, the smallest with carbs, and the medium with meat - I have one of those each for dinner and lunch. I also have little mini containers that are for my snacks (nuts, maybe some chippies, and a couple of small sweets), which I have once a day. For breakfast, I have an Optifast diet milkshake with a handful of fresh fruit blended in. This works for me but others might feel it's a bit same-same. I tend to struggle if there is a whole pizza, or a big dish of something - I'll secretly go back for seconds, thirds, fourths (I am not kidding). So I have to be really disciplined. I buy my vegetables in huge boxes from a local farmer, and my meat from an online butcher. This keeps costs down, and it makes my routine super-easy to stick to.
I'm not much of a fan of exercise, but I have a treadmill and rowing machine which I force myself to do 20 minutes on each day (combined).