Offered as an example, I just posted this in another thread re: a summer trip I just booked.
You could pick up 140,000 AA miles per person if each of you open a Citi and a Barclays AA card and hit the required spending to earn the sign-up bonuses on all four cards. (check the bonus terms to make sure you can still double dip with the offers you chose).
Same itinerary paid OOP:
Full disclosure: the problem with airline miles is that you can’t rely on reward space being available (or available for a reasonable number of miles) for the specific cities/dates you want to travel.
I have a trillion AA miles from actual flying, so I use them when it makes sense, and pay for leisure travel OOP when it doesn’t.