A Good Reason Not To Reserve Your Vacation Travel In Advance: Saving Money
This is the most important piece of travel advice I can give: Do not reserve the entire trip in advance.
You will want to change itineraries once you're on the ground. The weather may throw you a spitball. Machines break. You might meet a new friend and want to stay within range of his bed. You might run out of steam and decide to stay in City #3 until it's time for the international flight home.
So, more than any other travel tidbit I can type: Please do not reserve all your transport and every night of lodging in advance.
Go ahead and do the research. Prepare a list of air routes and preferred hotels and recommended sights, if that's your style. Reserve the first two or three nights. But don't make deposits or pre-payments beyond that (unless it's for a centerpiece event, such as a safari).
A problem with pre-payment is that you can pay too much. Travel industry professionals know that some people, particularly Americans, are nervous control freaks who are willing to pay a premium to lock down everything in advance. So a hefty markup is charged, an anxiety tax.
Another problem with pre-payments is that they reduce spontaneity. Pre-payments, combined with the American tendency to overschedule, can result in vacations which consist of people running from pre-paid hotel to pre-paid event to pre-paid flight. This argument tends to be a loser, however, since control freaks don't value spontaneity; I'll focus on the "paying too much" angle.
Here's an example I encountered today of why on-the-fly purchases make economic sense:
The published fare for a one-way "soft sleeper" ticket on the overnight train from Hong Kong to Shanghai is US$106 (HK$825).
The MTR, the company operating the Hong Kong train system, is currently promoting the ticket at a discounted fare of US$95 (HK$743) (same link).
But I walked up to the counter today at Hung Hom Station and bought a ticket for tomorrow's train at a point-of-purchase, last-minute, let's-move-this-inventory price of US$59 (HK$457).
Meanwhile, people who booked ahead paid more. China Trip Advisor is displaying the ticket at US$125. China Train Tickets is asking US$210, and China Train Ticket (no s) wants US$220.
There's no reason to pay US$220 for a US$59 ticket.
Make fewer plans, have more fun, and spend less money.
Pictured: Chinese soft sleeper train compartment (cutie not included).