Half Fiddler - I'm sure you'll have lots of mudcatters chiming in soon, but in general there are several "styles" of fiddling and you might want to be more specific about which you are getting into. A few are Celtic, Gypsy, Texas, bluegrass, old-timey, country, blues, jazz, etc. etc.

In the United States there are numerous regional styles. The "old timey" style is what I'm most familiar with. It generally tends to use a rhythmic shuffle bow and playing more than one string at once - double stops, etc. The broader "wall of sound" effect caused by bowing more than one string was probably developed for dancing where the fiddle and banjo were often the only instruments available, were playing purely acoustic, and needed to be heard above scuffling feet.