I have 50K miles expiring next month and would prefer not to take a flight to extend them. I was wondering if anyone here has ideas of getting miles quickly to prevent expiration.

Do non-flight mile earnings still extend the account?

Other than obviously flying, I'm looking at:
1. ordering flowers from teleflora - but these are hugely overpriced so wasting a lot
2. renting a car for a day - concerns me for the timeliness and making sure all the accruals work out. plus the time to do this, if you don't need it already, it a lot.