Soaking in water is not a great method :-) You can propagate JM's from softwood cuttings in early summer but they need rooting hormone and a proper growing medium. And heat.

Never tried growing from seed - need more immediate gratification and want only named forms (which are not obtainable from seed). But I have gathered seedlings from under mature JM's and shared with friends. If that is at all possible look for some of those. Or perhaps one of our seed growing regulars will chime in.

Here is a link that might be useful: Propagating JM's by cuttings

Thank you! Now I just need to figure out what a blood red JM seedling looks like... We have several red maples & a few JMs in the yard. Do they look very different before they've grown some? I'm having some trouble differentiating between the two (also posted this question in JM forum). :) Thank you!

I usually do what Gardengal48 does, just dig them up from under or near seed bearing maples.
I have planted seeds in flats and left them out in the shade for the winter and then potted them in the spring after they sprouted. I have also spread the seeds on a raked raised bed in the Fall and then lightly covered the seeds with soil. They come up like grass seed in the Spring.
If you are just now planting them after a winter in the fridge I would wait a little longer for them to sprout. I've had them sprout in the Spring in the refrigerator after being in the salad drawer for the winter. Outside is easier, according to my wife.
Mike

Here is a link that might be useful: My Garden