Improving on ice speed has many factors, but improving technique is one of the easiest fixes that can yield huge and immediate results. The more hockey I watch the more obvious it is that many players stand up too tall when they skate. Adopting a deeper skating stance will allow the skater to create a longer stride length. A long stride length equals an increased amount of time the skate is in contact with the ice. The longer the skate is in contact with the ice, the greater the opportunity to create power. A longer more powerful stride = faster skater.
As you can see in this simple demonstration, by getting slightly deeper I have a significant increase in stride length, which would lead to a longer and more efficient stride.
Beyond depth, developing lower body strength will also go a long way in improving on-ice speed.
And you can do that through a quality off-ice training program, like my Ultimate Off-Season Hockey Strength & Conditioning program.