As the Pyro facing a Soldier, do not wait to airblast the Soldier's rockets, as you'll waste precious time that could be used to just run up to him and flame him. Try to land some flares at the very least.
when I'm a pryo, and I turn a corner to see a solider, I flame him for a split second to light him up, then I immediately airblast. Usually I end up reflecting the rocket, but not always back into him. Then it's an easy flare/axe.