Stripes on a full-size fiddle: a handy thing for a beginner
A strip of colored tape about 1/4 in. wide, wrapped around the fiddle neck as shown helps beginners place their first and third fingers right. I don't usually advocate a second-finger stripe. I prefer to say where, on each tune, your second finger goes: either next to your first or your third finger depending on the string and the key of the tune.