Booking tickets with option of upgrade
 

I most often book tickets myself through airline (Most often Cathay Pacific or Lufthansa). How can I book a ticket with an option of seat upgrade?

1. Make sure the fare class is upgradeable
2. If there is also upgrade inventory available at the time of booking, you can fork over miles for the upgrade at the same time (in the case of CX, at least)

Obviously, make sure you have suitable upgrade instruments handy before committing to #1 because upgradeable fares are often substantially more expensive than the lowest available fares.

I see upgrade with miles, but no optional upgrade option
 

I have attached a screen from Cathay pacific. There is no indication that, upgrade is possible without paying extra miles. Is the message hidden?

By fiddling around the options on that page.. was able to see some changes to booking code. Got the idea. Thanks @moondog

There are 3 ways to upgrade on CX:

1. miles
2. upgrade instrument
3. fare difference between your fare and the fare for the cabin you wish to fly

#3 is not always possible, and when it is, you're usually better off buying the premium ticket in the first place.

To be clear, a 'free' upgrade is very unlikely to happen. You need to be prepared to fork over either miles or cash to do so, and your ability to do either will depend on a combination of the fare you've bought and your status in either MPC or M&M. It is not useful to give highly general advice in the absence of a specific example.

One point that is generally true for most airlines is that the cheap economy tickets are not upgradeable using miles, and if they are will only be upgradeable to the next class of service (in the case of LH and CX, premium economy).