One tip is... don't over do this. I was on LL for 9 months and developed severe lethargy and found myself slightly aenimic, as did my boyfriend after doing LL for a long time.
No matter what they tell you - these foodpacks *aren't* completely nutritionally sound, you do miss on a few vitamins and such.
If you have a long way to go, I suggest taking a break after about 5-6 months, do RTM properly, try to work on your relationship with food (most importantly work on self-perception and image issues too! Being curvy really is not the end of the world - it's actually healthier!) for a couple of months after RTM. Then depending on how well you've done, and how much you still want to lose you can do a Refreshers.
Other things I've noticed while being on LL long-term is ... you feel the cold ALOT more. And your stomach never stops rumbling! ... Not out of hunger, but it just gurgles all the time.