Yesterday I talked about how to book awards with layovers of up to 23 hours to see even more cities en route than would be allowable with normal stopover rules. Is it a good idea?

I'll review two recent 23 hour layovers I had, which were actually eight hours in London and thirteen in Frankfurt.

London

In London, I had to fly into Gatwick and out of Heathrow to make sure I could get an en route stopover in Tampa on an AA award.

Recently I had two clients of my Award Booking Service want to add a few 23 hour layovers onto their United award from Cleveland to South Africa. All the legacy US carriers have a rule in place that on international layovers, under 24 hours is just a layover, but over 24 hours is a stopover.

This distinction is crucial since no US carrier allows more than one en route stopover internationally.

For some, Lufthansa First Class is their aspirational goal. Using United miles, there is a (poorly kept) secret for how to get Lufthansa First Class seats: wait until the last week or even the last day!

Lufthansa only releases its first class availability to United right at the wire. For instance, I am sitting in the Lufthansa business lounge in Frankfurt right now, waiting to fly FRA-LHR-LAX on Lufthansa and United business class.

Reader Martin asks: I am trying to book IAD-CDG, BRU-IAD and trying to add my free oneway from IAD to ?? No mater which destination I choose the page always comes up with no available flights even though I check those flights separately and I can see there is availability. Any ideas?

It seems like I've gotten a similar question almost daily since I broke the news that you can add free oneways onto most United awards.

After writing a series of posts on how to add free oneways to your awards on the major legacy carriers, I got a flood of emails from people who had just booked an award and wanted to know whether they should rebook with my award booking service. In some cases, it makes sense, and I'll share one such case.

Brian emailed me saying he had booked a roundtrip award with United miles from San Francisco to Entebbe, Uganda for 160,000 miles in coach because for his preferred dates, there had been no saver award space.

I've written extensively about getting Free Oneways on United Awards. Yesterday I got an email from a foreign reader, asking whether he could get a free oneway on his United awards. Seeing no theoretical reason why not, I looked into it and found you can get free oneways on roundtrip United awards regardless of their origin.

I thought I'd share this because even for US-based flyers, this discovery can have value.

US Airways and American Airlines have merged since the publication of this post so it is no longer valid.

US Airways and United are both members of the Star Alliance, so many times you can redeem miles from either carrier for the exact same trip. In those situations, which miles should you use?

I've made a list of some clear situations to favor one mile over the other. The list can also be read as a list of situations to collect US miles versus situations to collect United miles though.

There are five basic types of frequent flier miles. I'll detail each, including how best to take advantage of them. Then I'll explain why it's important to diversify across the types (not just across frequent flier programs.)

1) Region-to-region based miles. American, Delta, United, US Airways, etc

Region-to-region miles are the most common type of miles. These miles can be redeemed according to award charts, so a flight from North America to Europe costs a certain amount of miles regardless of where in North America and where in Europe and regardless of the (valid) routing.

As a companion to the mega-popular Free Oneways on United Awards, I've made this video of me booking such an award.

Last week, I was working on a client's award from Portland to Seville, Spain with United miles. He had a tight availability range at the end of this summer, so preliminary searches of united.com proved fruitless: united.com was showing no availability from Portland to Seville in business class on his dates. Luckily I'm smarter than united.com, and you are too.

United.com is the best search award search engine of any of the US carriers, but it still has some flaws. It can find obvious routings through its hubs and its partners' hubs.