I plant them in disposable cups. I tend to watch them to see when they are asking me for water. About every 2-3 days till 2 weeks old, then they get transplanted, and go on a true water schedule which is about once every 3-4 days again depending on how much they drink. Remember that they are a weed, and they enjoy drying out from time to time, then a good drench. It gets much easier at about a month old when I start to only water them once a week, checking that the top 2 Inches of dirt is dry, with a very small amount of moisture. It shouldn't "feel wet" to the touch, but shouldn't be dry to the point it powders up.
If you let them dry out to where the sides of the pot/cup are showing gaps on the sides, water slow. If you water to fast you will create rivers that will miss a lot of the roots.
If you let them dry out to where the sides of the pot/cup are showing gaps on the sides, water slow. If you water to fast you will create rivers that will miss a lot of the roots.