Saiorse Ronan thinks Ryan Gosling is ''the best''.

The 19-year-old actress stars in the hunky actor's directorial debut 'How to Catch a Monster' and enjoyed the experience of working on the much-improvised film because every day was a ''surprise''.

She said: ''He's great. He's the best. He's very, very honest and self-assured; very confident and comfortable with who he is. And because of that we all felt immediately relaxed with what we're doing.

''Everything was improvised, really. We'd learn the dialogue the night before, and Ryan would make us ad-lib the whole thing. Every day was a surprise; you didn't know what was going to happen, where your character was going to go, or what relationships were going to form.

''It took me a while to get used to because I've never done anything like that before, but it was great. He was very humble, but very confident that this kind of thing would work.''

The Irish beauty believes Gosling's own acting experiences made him a better director on the film, which also stars Christina Hendricks and Eva Mendes.

She told website Refinery 29: ''I think his acting background did [help] in this case. He had such high respect for all of us. Anything he didn't feel was honest for our characters, he'd change. He respected the instinct of the actors because he does that himself.''