Root your cuttings in soil as they are pictured. Water well when the soil is dry, not sooner. The only way water will leave the container while your plants are rootless is by evaporation, so don't go crazy with the water. The main difference between the care of cuttings and rooted cuttings has to do with how often you might water, otherwise it's quite similar. But there is no particular benefit to leaving the soil dry for any extended time. If you always wait until the leaves are shriveling to water, your plants will regularly be on the verge of water starvation. You will better serve their needs if you monitor the soil instead. Put your plants in the brightest possible light indoors, like right by your sunniest south-facing window (assuming you're in the Northern Hemisphere).
You will have a clue that they are moving along and sprouting roots when those roots start to function and there is new growth on top.

and good luck!