A. Flying with Lufthansa and Partners
You will earn four points per euro on Lufthansa and partner flights. Elite status members earn an additional 2 points per dollar for a total of 6 points per dollar spent.
Partners: Adria, Aegean, Air Astana, Air Canada, Air China, Air Dolomiti, Air India, Air Malta, Air New Zealand, ANA, Austrian, Avianca, Brussels, Condor, COPA, Croatia, EgyptAir, Ethiopian, Eurowings, EVA, LATAM, Lot Polish, Lufthansa, LuxAir, Olympic Air, SAS, Singapore, Shenzhen Airlines, South African, Swiss, Tap Portugal, Thai, Turkish, and United.
B. Transfer Partners
You can transfer from Marriott at a 3 (Marriott) to 1 airline point transfer ratio. You can also get an additional 5,000 airline points bonus if you transfer in increments of 60,000 Marriott points. (e.g., 60,000 Marriott points become 25,000 airline points, whereas if you only transfer 59,000 Marriott points, you would only get 19,667 airline points).
Other ratios are Hilton (10 to 1), IHG (5 to 1), and Le Club Accor (2 to 1).
C. Credit Cards
Barclays Miles & More
Application Link (Target: 50,000; Current: 50,000)
Annual Fee: $89
Earning: 2x on Lufthansa, Austrian Airlines, Brussels Airlines, LOT Polish, and Swiss (several other small airlines as well); 1x everywhere else.
Benefits: 2 complimentary Lufthansa lounge vouchers annually (in the US: JFK, EWR, and IAD), companion ticket annually (very high taxes and fees), no foreign transaction fees, baggage delay insurance, and trip cancellation insurance.
D. Other Ways