Ok here goes my list from my short experience,
1. Please please please, test your any new equipment/accessories that you buy just before the trip(we tend to do that a lot) . I've learnt the lesson hard way and don't wanna others go through it.
2. Wake up as early as possible, you'll get many more days at your home to laze around, shoot during the golden hours (Ok if you are going to Ladakh then every hour turns out to be golden hour though

) , take rest or travel during the other time. And get ready during the evening golden hours again.
3. Don't pack up just after the Sun sets, actually till 30-40 mins after sunset you'll see very different hues in the sky. Obviously you'll need a tripod that time.
4. Be careful about the horizon, a tilted horizon can kill a potential great photograph.
5. Never ever waste the chance to shoot

Just stop the car or bike whenever you feel that you've a chance to get a good photo. Don't even think that on the return journey or later you'll shoot. You'll never get teh same magical light again.
6. Look out for unusual things, actually speaking you can find the unusual in very subtle things itself.
7. Don't just only use the wide angle lens for landscapes, use your telephoto(long lens) also for landscapes. You can leave out the unwanted subjects from your frame and isolate the subject of interest using Telephoto.
and the last but not the least, please don't forget to carry plenty of Memory Cards.
Regards,
KonfuSed
PS: there are few more things, will update when I recollect..