The best way to go to Sapa from Hanoi is to take the train. There are no flights and road journey is considered uncomfortable, long and less safe.
Best to book the train, both ways from a reputable travel agent from Hanoi to Lao Cai near the Chinese border and the transport by van from Lao Cai to the hill station of Sapa.
The train runs along the Red River. All trains leave at night from Hanoi and arrives at Lao Cai in the early morning. Trains also leave at night from Lao Cai and arrives in the morning at Hanoi. And so you save two nights of accommodations. It is better to stay one night in Sapa though it is possible to come back the same day if your flight is the next day.
There are different types of coaches of different prices. The standard is 4 bunk beds in a cabin. So shop around. It was a bumpy ride but after awhile I slept well perhaps all the walking around the Lake in Hanoi and woke in anticipation. After all the walking, the journey back, I could slept verywell too.
Best to quickly book train tickets as early as possible upon arrival in Hanoi. Then go to Halong or travel around Hanoi before going to Sapa.
If you think riding on a motorcycle in Hanoi is thrilling, you should try riding a motorcycle in Sapa. You could actually sit behind a motorcycle of the locals and they will charge between 15,000 to 30,000 vietnamese dong (less than US$2) for quite a long distance. I tried it twice and it was really great going up the slopes and feeling the cool wind, and at the same time admiring the superb scenery. The locals are very skillful so you don't have to worry, the only problem is that it is not possible to take photos while on the moving motorcycle as it would be dangerous.
All the trips to Sapa include some form of trekking to visit the villages and enjoy the mountain scenery, rice terraces, farms, waterfalls etc. These range from simple trek to nearby villages to longer treks to visit several villages. The trek is worth it because it is a wonderful experience, however be warned that this is not a stroll in the park especially if you are not fit. These treks may involve walking on uneven terrain, slope areas etc and made more difficult in rainy or foggy weather (some treks may be cancelled due to the weather). Therefore you must wear proper shoes and attire, bring water and sub-blocks (as most of the trek are in open terrain). The most important is to walk slowly and carefully, trying to rush will make it worse. The attached photos give you some idea of some of the trekking terrain in Sapa.
Most of the tourists who visit Sapa travel from Hanoi to Laocai (a town at the border with Yunnan province of China, seperated by a river and the other side is the town of Hekou of China) by overnight train. Usually, they will book their trip at the many tour operators in Hanoi, especially at the Old Quarters. The trip will include everything, from meals, transport, accomodation, trekking guide etc (a 2 day trip costs about US$80, and there are trips with longer days and you can even climb Mount Fansipan, the highest mountain in Vietnam). For the overnight train, tourists will get first class soft sleeper beds (4 beds to one room) and there are several trains usually leaving between 8.30pm to 10am at Hanoi train station and arrive at Laocai train station at about 5am the next day. Night train is good because it saves travelling time and accomodation, but it may not be easy for some people to sleep because of the vibrations (and the train toilets are not very good). For those of you who can afford, there is the luxurious Victorian train which costs a lot more (normal train costs about US$20 but Victorian train is a few times more). After reaching Laocai, there will be mini-buses to transport you from Laocai to Sapa (about 1 hour, the road condition is surprisingly OK). It is important to look for your name on the many signboards at the Laocai train station because there are many tourists ariving at the same time. Overall, I think the train journey is OK and please don't compare with train standards in Europe or North America.
The Sapa town is really small. With the cool climate, it's an easy & pleasant walk to all the various restaurants or hotels in the area. There are NO taxis plying the roads, so the only over options to walking is to take a motocycle taxi or to have a private car.
There are a number of different choices on whether you want to do this 8-10 hour ride in comfort (and pay a higher price), or rough it out. You can choose from hard seats to soft seats to hard sleepers (6 berths / cabin) to soft sleepers (4 or 2 / cabin). The better carriages are run and managed by private companies - the best being the Victoria Express (with its own private dining carriage - but is only open to guests who put up at the Victoria Hotel). We ended up booking soft sleepers from Tulico (US$56 per person for a return), which was very clean & comfortable. The cabin is also secure with a solid lock. We were also fortunate to have excellent travel companions in our 4 berth cabin, which made the journey very pleasant. Don't expect the toilets to be sparkling clean though.
IMPORTANT: Remember to retain your ticket stubs as they are needed before you are allowed to exit the station at your destination.
For trekking you will most need a local guide and maybe even transportation.
Most of the treks involve a minimum of 4 hours of walking along steep and usually muddy paths. To keep your trecks down to four hours you will need to hire a jeep or motorcycle driver to drive part of the way.
I would NOT recommend a motorcycle in this area the roads are muddy and treacherous even in the relative safey of a jeep. Plus if your not traveling in the summer it will most likely be raining!
We did two treks and used two tour companies. I can definitely recommend Nature Tours at phone (84)020.872094, internet, email@example.com. They listened to what we wanted and created a custom tour for the two of us so we got exactly what we wanted. They were also less expensive than the first trek we took. Another highlight is that the guides are local hill tribe girls and they see to prefer their local dress so you can get some wonderful pictures of them and get a wonderful insight into their communities.
The girl we had was a wonderful guide and took us into her own village.
Pictured here our guide and another friend at a local waterfall.
If your unable trek or unwilling to trek in the Rain (remember its quite rainey in Sa Pa) then you may want to visit Sa Pa between Saturday and Tuesdays when the Minority villagers gather in one place to go to the market.
There are quite a few markets available that you don't have to trek to reach them, just hire a bus or car...
The best way to go to Sapa is to take a night train from Hanoi to Loa Cai and then take a bus to Sapa.
Note Loa Cai seems to be totally lacking in charm so there is no reason to stay there anymore then you have too.
You can book the night train, shuttle from Loa Cai to Sapa from any hotel or travel agency in Hanoi
You will want a soft sleeper for the train. We had heard that the train was a bit expensive but when you realize that you are saving a night at a hotel you realize it's pretty reasonable.
Its also a pretty hassle free way to travel. You can book the train and transport to Sapa from your hotel or any travel agent.
The train provides a sweet roll and a bottle of water per person and people are selling sandwhiches, drinks and coffee on the train also...or you can bring your own snack.
I would recommend bring tolet paper, sleeping mask and maybe a silk sleeping liner for on the bunk.