Are they spring-flowering or autumn?

I'd plant them in a shallow pot (about three inches deep)with excellent drainage. I'd use a gritty mix and I'd probably plant them on the surface then cover with fine grit about an eighth of an inch diameter.

The sooner planted the better - otherwise you may need to keep the pot under observation for a year or more (with no obvious action to cheer you up).

Plant thinly - and, if you have enough seed, plant in more than one pot.

If you know the sort of crocus you have you'll know whether it's an alpine sort (keep outdoors and avoid drought); or a drought resistant sort; or one that needs to be outdoors over winter to be frosted so the seed coat splits for spring.

Once they come up - leave them in the same pot for one to three years to grow on. (If they're showing plenty of leaf delicately scrape away the soil to check on bulb size. Just remember that bulbs in action look more like carrots than they do respectable dormant bulbs.)

Hope you get something yummy from your seeds.

I think my crocus are seeding around my yard. I noticed about 3 dozen single strands of crocus foliage with now blooms near my established clumps. Plus some have come up in the center of other plants, that I know I haven't planted there. That is in a bed across the driveway from my largest patch of crocus.