ORIGINAL: psuguru
Use sharp blades in the Xacto knife and in any razor blade plane you might use. if you're paying $100 for a kit $5 for blades isn't too much of an imposition.................
A razor saw is a good investment too.
And make sure your fingertips are away from the edge of any straight ruler! You don't need to lose a finger to make the obligatory blood sacrifice to the wind gods !!
Make sure that straight edge is METAL. Sharp blades easily "bite" into and ride up on the plastic straight edges commonly sold as builders sets....they also ride through your fingertips shortly after that, ask me how I know. [:@]
+1 on the razor saw, get the one sold with the miter box so your cuts are square (stick wood). Get a Dremel and a Scroll Saw (Scroll Saw especially for cutting your own parts if you so chose later on) <- two most useful things I've bought. A drill press will also come in handy down the road (also $100 at Lowes). Forstner Drill Bits, they won't chew up your balsa like a regular bits will (Wing bolt holes and any other holes drilled in Balsa)