No, it's by no means difficult to get to Tibet when already being in China. But if you want to avoid trouble and save quite a bit of money then you might find the following hints useful:
Start from ChengDu
Unfortunately--except for the extremely cute Giant Pandas--ChengDu is quite boring a city. But for reasons unknown to me it is where the right travel agencies sit. As long as you want to stay legal you have to involve an agency (see 'Permit' below). When I was preparing my trip I found one incompetent agency in Shanghai, did not find the one Tibetian agency supposed to sit in BeiJing, and couldn't avoid stumbling over at least half a dozen agncies in ChengDu although by that time no longer needing them. Situations will change, but as long as you don't have any better information, then ChengDu is a save bet.
Regulations keep changing, but as of June 2007 you do need a Tibet Permit for entering Lhasa. The main idea of this permit might just be to cash in on you, it costs some 500 or 600 RMB. But you won't be able to avoid it: Without it you will not be able to check in for a flight or board a train. Have it handy when boarding.
Once in Lhasa only some larger hotels may want to see the Tibet Permit (and are allowed asking for it!), but by and large nobody cares.
The only reasonable way to get hold of a Tibet Permit is to go through an agency. They can organize for it in a matter of 3 to 5 days. But agencies are legally required to sell the Tibet Permit only as part of a 'group package'. This is where the old rumour comes from that travelling to Tibet is only possible as part of a packaged tour. In reality, these packages can be anything you like and the group size can be as small as 1 (as it was in my own case). So don't worry!
There might be agencies with quite strict handling (CITS is one of them), who aren't exactly legally wrong when saying that they have to organize your entire tour from entering until leaving Tibet. But if you happen to come across an agency which keeps insisting on this strict handling, then just leave. Because at least in ChengDu there are agencies, which handle things less strict: You just have them organize your transportation to Lhasa and they will do so and organize the permit as well. I once in ChengDu came across an agency, in which the agent tried to convince two French not to book the entire trip with them, but only the first transportation leg! And honestly: You need transportation anyway and will, thus, welcome the service of an agency anyway. It's just that you can't avoid paying for the Tibet Permit.
There also is a Travel Permit, which allows visits to so-called 'closed areas' far outside Lhasa. I have no own experience with this Travel Permit, but intelligence says it sometimes is indeed checked by police checkpoints.
Anyway: You don't care upfront. Once in Lhasa the agency organizing any further travel (see below) will take care and can arrange it easily.
Tibet Travel has some overview information, including some areas of interest, for which the Travel Permit is necessary.
Where and when to organize for what?
In ChengDu, before setting out, have an agency organize for your transportation to Lhasa (train or flight) and the Tibet Permit. It might be a good idea to have them reserve a guest house for the first few days or even a 2-day sightseeing tour of Lhasa. You will need a bed anyway and honestly...without a guide in the first days you will probably not understand anything of what you see inside the monasteries and htemples. And that would be an extreme pitty! The guide will also pick you up from the airport (or train station). Just make sure you get a Tibetian and not a Chinese guide. Downright ask the agency! A Chinese guide will not be able (or even willing) to explain all the Buddist customs and Tibetian history. Also, the local guides more easily get hold of tickets for the Potala Palace, which indeed are restricted in numbers per day.
I do not recommend organizing any more from outside Lhasa for cost reasons. It is not so much that the agency would overcharge you (in the end they just call their Lhasa partners), but you have to pay for everything with the number of people travelling with you. And in most cases your are travelling alone or with just one other friend. That makes things expensive. If you are a group of four, then you can consider booking more in advance as more people share costs for guides, drivers, and/or cars.
Which agency to take? Check latest gossip in ChengDu. There was one looking OK to me, which was located on RenMin NanLu (????), opposite Bank of China, in the foyer of an associated guesthouse, as usual with a lot of English offers pasted in the windows.
If you want to see more than just Lhasa (and you better want!) then in Lhasa, after arrival, go to one of the black bords outside some guesthouses. There are several, a pretty active one is at the Snowlands Hotel (though the hotel itself recently got quite mixed reviews). You'll find notices by backpackers looking for other people planning to go to the same places they have in mind. The reason is that transportation within Tibet is mostly by rented car, often off-roaders. And renting a car with driver (in China you aren't allowed to drive yourself unless you have a Chinese driving licence) is expensive. So people try to form groups to share costs.
If there isn't anything interesting then post your own note. Obviously, being reachable by mobile phone makes sense then. But SIM cards are so cheap in China that you most likely have one by that time anyway already. China Mobile works throughout Lhasa and along major streets outside Lhasa. Contact by EMail also works. Several guest houses have PCs nowadays. And if not: There's a really good café on DanJieLin Lu (????), opposite Snowland, in a small yard accessible through an archway. WLAN free, PC usages costs something.
For the actual trip (like trips to various lakes or to the Mt. Everest Base Camp) there is no shortage of agencies in Lhasa, who will be at your service. Your hotel/guesthouse might be able to help, too.
This approach, organizing the details in Lhasa only, obviously requires that you are not under time pressure. It can take some days until you find the right people to join. That also means that you most likely will not want to book transportation back to Mainland China (or onwards to Nepal) in advance but only once your Tibet trips are confirmed.
Transportation Options: Train, Flight
For the trip between Lhasa and Mainland China there are two options: train and plane.
Getting flights is straight forward and there are plenty available from many locations. ChengDu, Xi'An, BeiJing, ShangHai are just a few options.
But seriously consider going one way by train! The QingHai Plateau is a fantastic sight to see! Rough travel time from Lhasa:
- XiNing: 24 hours
- LanZhou: 27 hours
- Xi'An: 36 hours
- BeiJing: 48 hours
- ChengDu: 46 hours
All trains go via XiNing and LanZhou. The BeiJing train goes via Xi'An.
I recommend taking the return trip by train. Reasons are:
- Trying to get tickets towards Lhasa can ground you for days or weeks. Especially tickets from Xi'An to Lhasa are next to impossible to come by and if then only in Xi'An. (Even CITS can't get them anywhere else...)
- The trains starting in Lhasa tend to be less early sold out. Chinese tour groups do the trip the other way round, which is why trains to Lhasa are sold out weeks in advance.
- Organizing the ticket is fairly easy in Lhasa. All travel agencies and maybe even your hotel/guesthouse should be able to help you.
- You see the fascinating QingHai Plateau on your first day on the train, while you still enjoy the ride. You can then sleep through the second day or organize you photos already...
- You can short-cut the trip by getting off in XiNing or LanZhou and taking a flight from there to many locations (including BeiJing) within China. In this case you better have your flight ticket already...neither city is worth spending much time in.
You might have read it between the lines already: Train tickets sell quickly, so organize train tickets as early as possible.
Which class to take? Depends a bit on your budget and preferences as always. China trains are save, generally comfortable, and hence a very good travel option. For a 48 hour trip I would naturally avoid taking seat tickets (if you aren't French that is...I met three French who got to Lhasa on hard seats...they were toast upon arrival). Most backpackers go for Hard Sleepers, which offers OK beds but no compartment doors. If you like it a bit more quiet during the night opt for Soft Sleepers. I believe my soft sleeper ticket from Lhasa to ChengDu was something around 1000 RMB. Not cheap...but hey...it's a 46 hour ride...and 22 RMB/hour isn't so bad, is it?
There is food available on the train. You may want to bring some fruits and snacks, but there would be a dining car (I didn't try) and there even is a food car coming along the aisle in the evening with some simple but filling rice-and-vegetable dish for 20 RMB. Certainly, as with all Chinese trains, there is hot water available for free in every car.
Information as of June 2007. Please be aware that Tibet policies tend to change easily and without notice. Check with your agency to make sure your plans will work out!