just basic shit really, lots of water. coffee is good appetite suppressant. count calories. veggies and lean protein, your food should look close to how it looked when it was growing (as in not a cookie or bar.) make your calories count nutrition wise (don't live on rice cakes and hard candy) as far as high or low restriction, do what you can keep up. no point doing 500, 500, binge, 500, binge, etc. control portion size and/or reduce calories in the rest of the day instead of cutting out foods so the cravings don't get out of control. diet is more important than exercise. do weights not just cardio, good for burning cals and good for bones.
this is all stuff that could be applied to a normal weight loss diet.
if you're trying to lose weight by a specific date, you can psych yourself out and trigger binges or go too hard and trigger binges or burnout or side effects. this part is hard, im still learning this, but try to just make every day good and not fixate on whatever deadline. if you lose weight steady, then in the future you won't have to try to cram 3 months dieting into 3 weeks. fact is if you need to lose a ton of weight fast you should have started earlier and kept it up. sorry if that's harsh but it's something i tell myself too.