I'm just picking up the fiddle after years of playing mandolin. The mandolin playing has certainly helped me in the violin fingering - and I've resisted the temptation to mark the fingerboard in any way.

Strangely enough, I find I get more accurate intonation by NOT looking at the fingerboard at all, but doing it all entirely by feel. But it does take some mastering! Luckily, I learned some viola at school (over 50 years ago, admittedly), so the actual bowing action isn't too bad.

Practice, lad... practice... that's what I tell myself.