This was the Guangzhou train station during spring festival a couple of years ago:

This is why I NEVER go anywhere during holidays in China.  But if you are going to go, book as early as you can and be prepared for the most miserable experience of your life.

First Spring Festival? Stay home. You'll enjoy it much more!

Stay the f*** home!  It is the worst nightmare to travel during this holiday.  Have you ever read about all the factory workers and migrants who work in the cities?  Yeah, they all go home during the festival, all hundreds of millions of them... on the same day, and are crammed into trains until the doors are bulging out.  Not to mention the high school ,college students, constructionn workers all going home as well.

I suggest enjoy a vacation in your home city, but avoid the subway at all costs for a day or 2 after the traffic settles down.  Be like pogger and grab a camera, stand on a tall building or highway, and take some photos.  Enjoy watching the mass transit system collapse while eating a cinnamon roll from Dunkin' Donuts in the morning, like I will.

Securely fasten a 6 inch nail point outwards to the wall of your apartment and spend the holiday head butting it. The pain will be a lot less intense than traveling during Spring Festival!

ALL the trains for about 3 days before until about 3 days after will be fuller than a sardine tin! The difference being Sardines are dead and don't need toilet facilities. Think about that, the trains are that full (esp in 'hard seat' areas) that it is impossible to get to a toilet, many journeys are over 12 hours, think about it, what do you think happens?

very

It is possible to travel during Spring Festival, just do it judiciously.

1.  If possible, if you must take the train, book early, online if possible.

2.  Take a D, G, or the new very high speed train wherever possible.  They cost incrementally more money and are thus shunned by the migrants returning home.

3.  If you must take a regular train, then take a K or a T train.  Do not take a simple numbered train -- that will be h*ll.

4.  Then again, if you are on a K or a T train, try to get a hard or soft sleeper.  Most of the rolling stock for the hard sleepers on the major lines is very decent these days and the cars are quite new and well-maintained.

5.  If you get a hard sleeper, opt for the bottom bunk only and make sure that you give all to understand that it is your bunk and not their sofa.

6.  Very often the station clerks will tell you that the soft sleepers are sold out and most of the time this is not true.  When you board the train, head for the soft sleeper and talk to the porter.

7.  As Hugh writes above, avoid the 3-days before and the 3-days after.

Last year I had decided to travel to Japan, but didn't realize I'd be coming back before Spring Festival. I returned about 2 days before, and I could not get a train to a smaller city until the next morning, and that without a seat. It wasn't a big deal for me, because I could sit on my luggage, and I only traveled for 3.5 hours. Buy your groceries beforehand, and stay home. Nothing will be open the first few days and you'll starve.

Imagine sardines in a can..

Last year wasn't too bad for me.  But all I was took D-trains exclusively, and all routes involved smaller stations.  Only one route purchase was done more than a day in advance.  I dunno...it wasn't as bad as I had imagined.  Me and the gf had seats, and I don't recall seeing a bunch of standers...

On the other hand, I just flew back into China the other day.  Departed the States on 12/31, landing in Shanghai on 1/1.  Wow, the subway system was unbelievably packed (transiting from Pudong airport to the South bus station).  Truly the sardines in a can feeling with the added bonus of me dragging around a big old bag (weighed in at over 60kg ). I can only imagine what it would be like during the peak times of Spring Festival...

It'll be the apocalypse.