Tip #1: Practice Effectively
Someone once asked a fiddler standing on a street corner in Nashville, "How do you get to the Grand Old Opry." To which the fiddler replied, "Practice son. Practice." How right that fiddler was! No amount of theorizin', analyzin' or other such activity will get you where you want to be. But deliberate, regular and well-planned practice will improve your playing no matter what your level.
I envision good practice having three components. The first of these is passive and active listening. Passive listening means hearing good recorded fiddle music all through the day. This means putting on a fiddle tape or CD while you're eating breakfast, driving to work, making dinner, etc.
Active listening is critical and deliberate listening to recordings a fiddler of your choice. Listen to rhythm, bowing, melodic passages, chords. Try to soak it all in. Pay attention as if it were Monday Night Football, The Man Show or some other such engrossing TV programming.
The second component is to practice specific techniques that improve your left-hand and your right-hand.
The third component is tunes. You can learn these by ear or off the page or some combination. Work on some easy stuff for personal encouragement and for a challenge always be working on something that is over your head.
In order to plan your practice use my Old Fiddlers Practice Log. Print out a copy each week from the link or download it in PDF format and keep it handy. Fill one out each week to plan your daily practice and then stick to it.