So, if the soil is humid i don't even water and just let them expand the roots into the humid soil as it dries out, if the soil is dried at first you sould water just enough to get the bottom portion humid at most, so for a 12l you might need just 400ml to 800ml of water depending on your soil's water retention capabilities.
And yeah start wet dry cicles right away, check any of my latest diaries to check how i did on the transplant if you wish to. If you don't wish to i will just say, i watered the initial pot on lets call it day 1, then transplanted on day 2, then only watered again on day 4 as the soil was still humid and my soil mix has big water retention capabilities, therefore when i watered i had to go from 75ml per plant per watering to 750ml per plant per watering, i wet the whole soil because as the roots expand they drink the water retained in the soil that is in direct contact with the roots first, and as they expand they drink the water in the soil that was not in contact with the roots, so your gonna want to have the lower portions of the pot wet so the roots feels compeled to move there.
I hope it helps, keep it up, nice grow.
C ya around growmie.