Finished these drawings for a couple of ships that are canon in my AU, so I figured I'd post them together. Here are some of my thoughts on how they would meet:

Thunderlane x Double Diamond
They meet at a ski lodge, where Double Diamond is a ski instructor, when Thunderlane takes Rumble on holiday. Thunderlane starts crushing on the other stallion, finding himself drawn to Diamond's friendliness and infectious positivity, and Diamond finds Thunderlane's valiant (if unsuccessful) attempts to ski and his good-naturedness about it all very endearing.
This culminates in an incident during which both of them are nearly caught in an avalanche on the way down a steep slope, leading to Thunderlane swooping in just in time to save Diamond before both ponies are buried in the snow.
Once they're safely back on stable ground, Thunderlane (uncharacteristically nervously) asks Diamond if he'd like to get coffee or something, later, if he's not busy, and Diamond warmly agrees. They're both drawn to the other's passion for their job — Thunderlane's status as a Wonderbolt, and Double Diamond's primary occupation as a professional skier — as well as their mutual love for stormy weather.
In my AU, they're now happily married and have a child named Snowdrift.

Princess Luna x Twinkleshine
Twinkleshine shows up to Princess Luna's Night Court with a concern one evening and is immediately smitten.
She starts making an effort to visit every night, coming up with more and more ridiculous reasons to see Luna.
At first, Luna is kind of oblivious to the fact that this pony has a crush on her, but finds herself starting to look forward to seeing Twinkleshine every night (which she realizes after Twinkleshine misses a night because she's not feeling well). On the other hand, Princess Celestia notices fairly quickly that this pony always seems to be there to see Luna, and when Twinkleshine very nervously approaches Celestia about her sister, the Sun Princess is more than willing to help.
Eventually, Twinkleshine appears in the Court one night with a proposal instead of a grievance: she wants to ask Luna out on a date with her.
Luna agrees, still a little hesitant to get involved with Twinkleshine because she hasn't dated in so long, but wants to give it a shot because she really likes this pony. They hit it off really well, finding common ground in their shared love of magic and astronomy.
In the future, they are officially together and have two children, Nyx and Hestia.