Since overwatering is such a common mistake for newbs, I have come up with a simple idea for the experienced people interested in helping the newbs. What if "you"(meaning pro grower) make videos with different watering techniques. Have the videos show upclose comparisons of when there is not enough water, when there is too much, and when it's just ahhh right. It could be in extra soil in a small cup, you don't have to water an actual plant. Let me know if your up for it. I will rep ya.
Overwatering is a pretty easy thing to notice and remedy, if the leaves feel full and are sagging just cut back a little next watering. There are a lot of factors that go into how much water your plants need so no single handful of videos are going to provide definite answers.
A lot depends on your climate - mine is hot, dry and sunny every day throughout the growing season. My girls are now using 8 litres a day each - I water until it comes out the drain holes. And if I don´t water every 24, the ladies are wilting by 36. Overwatering is just not a factor for me.
8 a day, do you live on the sun. Thats alot of water. Thats what it's like 'in the summer here. how big are they to be using 8 a day each !
I don't think the difference between the soil top being dry vs. the soil throughout being dry is easily discerned on a grainy video, which I have neither the time, money, nor inclination to produce for you. It is far better to learn how to water a plant than to copy a video of a plant being watered.