Updates:

Dos:
1) Apply Railcard for cheap train tickets (in UK)
2) Bring easy-to-wash clothes (e.g. t-shirt, jeans, etc.) which doesn't require much attention.
3) Bring a few pieces of winter wear (1-2 would do) ONLY because Malaysia sells sucky winter wears. Out of fashion and not thick enough    > Get it over there.
4) Yes, you can work part time. But do not spend too much time in that until you neglect your studies. 

Don'ts:
1) Waste your time on applying HSBC saving accounts. They are very fussy though they are famous/good/international/professional. Go for Natwest for instant approval. Barclays (not recommended) requires you to have a ertain amount of cash in your saving account or else you'll get penalty.
2) Bring dry products ONLY to avoid quarantine by Immigration department.