There's only one real way to test your homemade skis: ride them and ride them hard.  It's also a good idea to test ride them in all conditions to get a feel for their performance.

For safety, periodically inspect each ski.  Pay close attention to the ski's camber, flex, and appearance.  These properties may change significantly from one day to the next.  Don't be surprised by rapid degradation.  Use your best judgment to determine whether your home-made skis are rideable.   Take note of any cracks, chips or potential failure points.  Careful observation can help identify design and construction problems.  With enough practice, you can work around problems in the design and layup phase to create great skis.  

Another way to test a ski (if you're not too attached to it)  is to intentionally break it.  Breaking a ski may expose the ski's weakness right away, and appropriate counter measures can be used to improve future designs.  However, note (and be warned) that breaking a ski is very dangerous.  Exercise caution and protect yourself and others if you consider this method of testing.

Happy ski building and riding!!