Feeling naughty again

I'm working on this plate and I want to use some spit bite on it but there are areas which I don't want to be to darken more. I covered some of the areas with varnish but I didn't want the edges to be sharp so i poured some spirit on the plate and left it dizolve some of that varnish and using a brush i gently tryed soften the edges.

I wasn't to happy so when I sprayed the aquatint I used more on the edges to block the acid cording the plate.

I left it to dry as I was kicked out as the studio Is closed for lunch

The areas that are darker blue I used more layers of aquatint with the hope to have some gradient when I apply the acid.

This way of working, not knowing what are the exact rules, is it something that artists do? I don't know, but I love working this way. I have few books at home looking about printing but in worried that the more I know the less I will feel like a rebellious kid doing something naughty. There is something nice about this feeling.