"Mike W." wrote in message
...
[...] So what is the process for choosing an alternate?

It can be quite complex, especially for Part 91 because so much is left to
pilot discretion. Basically, an alternate needs to be forecast to meet the
requirements given for that airport (its "alternate airport minima"
specified for a given instrument approach at the airport). One is not even
required to have an alternate if the intended destination meets some basic
weather forecast requirements. See FAR 91.169 for the nitty-gritty.

However, in reality what you're trying to do when selecting an alternate is
to provide for a genuine Plan B. This means you need to consider the
weather that is causing you to want an alternate in the first place, and to
pick an airport that will not be similarly affected. This may mean picking
one that's not in the same valley, on the same side of a mountain range,
near the ocean shore, etc. Of course, you also need to pick an airport that
is suitable for your airplane and your piloting skills.

A person could write a whole chapter in an IFR training manual on the topic.
Between this post and many others you'll get, maybe you'll get an inkling of
what's actually involved.

Pete