I've done almost all my kit building with CAs. Putting the parts together and hitting with thin CA works really well. I also have thick or medium around for when it's easier to put glue on then put the parts together. Here's a hint, put CA on one part, shoot the other with accelerator. Touch the parts together and get an instant bond.

Most all my cutting and fitting I've done with an exacto and sandpaper. A miter box as mentioned is a bonus.

The most essential tool I use is a stiff, flat sanding bar. I have a t-bar that is actually rather long that I use for most sanding.

It's been a while since I've done serious building, but I imagine the laser cuts must just pop together, consindering it wasn't that long ago that the best di-cut kits could be almost totally built with out any glue or sanding at all. Just pop it all together, and add glue later.

It does pay to ask around about a specific kit though. Some kits are just designed better than others, have better instructions, etc.

I've never used a jig, just a flat board with homosote (from the hardware store) on top. And I've built double-tapered wings with out any trouble. A good kit has things like alignment tabs on the ribs to keep things straight.