My girlfriend wants to go on a shitton of vacations this year and I figured the best way to save money is by earning frequent flyer miles.
She wants to go to Portland where her family lives, and the closest airport for us is BWI in Baltimore, so this trip is going clear across the country (what I equate to as being most expensive.) She also wants to go to Disney World in Florida at some point in the year too, and I know plane tickets aren't exactly cheap for there too.
So I'm wondering how worth it would it be to get a credit card that offers miles for the Portland trip, and hope that it'll be enough to alleviate the expense of the Florida trip later in the year.
I'm trying to study up on how to do this, with no prior knowledge of how flier miles work. I just learned that it does not equate to 1 flier mile equaling one physical mile of plane travel, which is bullshit.
The thing is, I don't even know where to begin. I'm looking at airfare from BWI to PDX and seeing what airlines typically fly there in hopes that those same airliners fly out of BWI to wherever in Florida so that I can just get a credit card from that airliner and cover all my bases.
That's not how miles work.
They're for frequent flyer that do at least 30+ continental flights per year to get some rewards/more comfort. For anyone else it's just to get a cheap upgrade once upon time or buy some gadgets..
If you want to start collecting miles there're only two real options, Miles&More and OneWorld (for the US Delta is also an option)
I use Miles&More as example
With the basic credit card you earn 0.5 premium miles per USD spent and the cheapest flights start at 10k miles (discount) normal price is about 30k miles. So that's spending $20-60k on your CC for one flight for one person.
If you don't fly a lot anyway it would be better to get a CC with 1% cashback.
1. Get the Citi AAdvantage Platinum Select card. It gives 50k AA miles when you spend $3k in the first 3 months. They fly between BWI and PDX though not directly. The annual fee is waived for the first year, cancel the card within 11 months and you'll pay no fees. You won't lose your miles.
2. Get the Chase Southwest Premier card. It gives 50k Southwest points for $2k spend in the first 3 months. You'll pay a $99 annual fee the first month, you can't waive this one. It's worth it for 2 free RT flights. Cancel as soon as your points post if you want, you won't lose your points.
Space these out if you don't spend much money, put all your spend on them (pay them off as soon as you get the statement, don't need to pay them before that).
The 50k AA miles is enough for you to book 2 round trip tickets anywhere in the US on mostly AA flights. You can check for award availability now on aa.com before you spend much time on this. You are looking for the Mile Saaver tickets, if those are sold out it will be more than 25k RT per person.
The 50k Southwest points will probably get you 2 RTs or more. I generally spend an average of like 12,000 per round trip so you may have a few left over after booking, maybe a ton (booked some for 3500). Unlike AA theirs is not a fixed chart.
 You can fly nonstop from DCA to PDX if you want on Alaska. Alaska has a credit card as well from Bank of America. It doesn't have a minimum spend requirement, just use the card once and you'll get 25k Alaska miles. Not nearly as good of a deal.
 You might also want to look into booking your flights with Spirit (shitty airline but cheap as fuck for this route) or Southwest with straight cash. It's a cheap, direct route from BWI so it might make more sense to get a credit card to earn hotel points for the stay instead - hotel stays can add up like crazy.
Another fun tidbit of information worth knowing is that there are only a few actual "flight companies" or whatever you want to call them. Think of it like how Sierra Mist, Gatorade, and Lays are all different brands, but Pepsico is their parent company. It;s the same way with flights.
What I mean by that is some points are transferable to other airlines on your CC's website, i.e. Delta to British Air (I'm not sure if that is a real trade you can do, just for the sake of the example). So if you are booking a flight from New York to London, it might be 47,697 points if you book on Delta, but the same flight could be 37,398 points if you book with British Air, so obviously you can get more out of your points by booking with British Air. You can only transfer points in certain increments, and once you transfer that particular amount once you can't transfer them back or to another airline, so check and plan accordingly.