Very interesting Konstantinos. I agree with Shawnee. "Play it by ear" - a common expression in BE - can be positive or negative. As with everything it depends on tone of voice and context. So it could vary from "I'm adapting what I do to changing circumstances", through "I'm not sure what will happen" even up to "Don't tell anyone but I don't really know what I'm doing". Shawnee's "we'll see how we go" is warm, familiar and positive.
My School and Office Μπαπινιώτης gives "για ενέργειες που προσαρμόζονται στις εκάστοτε συνθήκες" suggesting that the phrase in Greek only has a positive meaning.
Could someone explain about "θα κάνω του κεφαλιού μου".
Thanks ioanell and shawnee. I suspected that would be what it meant. In BE we have have a colloquial phrase - to do something "off the top of your head". It just means either without any preparation or without giving any thought to something not necessarily involving risk or negative consequences and I think it can include both your versions. Without a verb it often introduces a quick approximate estimate of something. E.g. "How much do you think we would have to pay to fix the roof?" "Off the top of my head... £300."
To me, θα κάνω του κεφαλιού μου means "I will do whatever I feel like doing, not heeding anyone's advice." It is an expression of recklessness.
Tράβα μπρος και μη σε μέλει /Θάρρος η ζωή μας θέλει [...]
Τράβα μπρος και του κεφαλιού σου κάνε / Τράβα μπρος κι όσα έρθουν κι όσα πάνε...
is a song from a well-known 1960 Greek movie, where a young woman sneaks into a Greek Navy ship, where her boy-friend is doing military service. The words clearly mean "Push ahead and don't worry about anything; push ahead and do whatever comes to your mind, and let the consequences fall as they may."