1. First and most importantly is the front face or soundboard of the guitar. Look at the inside edge of the soundhole. If the guitar has a natural finish, you should be able to see the grain of the wood wrap all the way around the inside edge to the inside. If you see 2 or more layers, it's laminated. I've seen some that almost look like the edge of a piece of plywood with many layers. This technique cannot be used on some guitars with very dark or painted finishes. The inside edge of the hole is too dark.
2. Back & Sides - Look at the back of the guitar, then look inside the soundhole at the same spot on the other side of the back. The wood grains should match. If not, it's laminated. Do the same as best you can with spots on the sides. Again if the guitar has a very dark or painted finish, this technique cannot be done.
Bob, Gman ( o )==#