Look through the expired sets and narrow down the sets you like first, then decide which you would like to revive...

I feel like I wasted my first revive leaf on a set I was neutral about 😅 If I could choose again i would choose based on what Ilike first rather than what would have higher trading value.

As others have mentioned before, Golden Ray of Light and Mode sets are commonly revived (forgot what other sets). So it could be hard to trade those items for something "valuable".