Thank you so much for this! I'm new to colouring, and while I do like photoshop, I find Sai a LOT easier to use and less laggy for my laptop. Also Sai's Blur/Blend brush is like 100x better. This is going to help a ton, thank you!
No, I doubt it'd be one layer. Because the fact remains the same: you would need to change the way the style. If you set the entire layer you drew on to "luminosity", it would all be bright and neon when not all of it should be this way in most cases. Of course, even if you did use thousands of layers you could always just merge them all together if in a folder with one click, or manually do it by pressing the button over and over (but be careful, as often you will find yourself messing up with the light value, so it's best to just put them all in a folder). Excuse my English as well. ^^'