I was running low with my lightning crystals again yesterday. So I sent out all 4 gatherer retainers of mine for lightning crystals, which took about 40 min.
I then queued up as AST or SCH for Bardem's Mettle / Doma Castle / Castrum Abania dungeons (I am currently leveling AST and SCH, and they are usually pretty quick with queues).

I ran two dungeons within the 40 min, and came back with a crap load of loots. I then turned them all in at GC, got the seals, bought ventures coins.
Got back to the bell, and refreshed their lightning crystal gathering trips. It worked quite well.

Btw, apart from lightning crystals, water crystals seems to be depleting really fast for me (instead of wind). I probably use my ALC a lot more then my GSM and CRP these days.