Home cocktail classics - how strict are you?

What intrigues me in cocktails, and drinking/eating is exploration of new flavours and combinations thereof.

I was just reading someone's post on Negroni, and it made me think: do you guys always follow the recipes , or are you able and willing to adjust them for your current craving?

Negroni is a very simple one, right? Equal parts 3 ingredients, stir, done. But then, if I want it extra bitter - I'll personally absolutely add more Campari and maybe even extract some orange/grapefruit oils on top for an extra bite.

Do you do that or do you stick with the recipe, and try to go for a different drink altogether if you want something different?