Here's my method of taking down pirates when they jump me while I'm flying between planets.
From first shot to last, this took 25 seconds - that's 5 seconds per kill.
As soon as I know I'm being jumped, I check my phase beam and shields are at full capacity. Then, I turn towards where the enemy ships are warping in and I hit full reverse thrust. Then I just blast away as they try to close range. If you have fully upgraded phase beam and shields, and if you do it right (focusing fire on one ship at a time), they should all be dead before they take your shield down.
Be careful of your shield though - doing it this way presents the bad guys with an easy target, so if you're in range of their weapons you will take a pounding in a short space of time.
I also fly in reverse when pirates attack, however, I find photon cannons to be much more effective in defense. With all cannon damage upgrades and all accelerated fire upgrades, pirates never even touch my shields.
Yeah. I don't like photon cannons. They don't auto-target, they don't hit the target instantly, and they don't have the range of the phase beam. They're just too clumsy and unpredictable for my liking. I prefer the phase beam for the same reason Obi Wan Kenobi prefers the lightsaber to the blaster...
Sure, photon cannons are great if your enemy goes straight, as your HUD displays his predicted course based on a straight path, but enemies don't always do that, so some shots go wide. The phase beam is a much more elegant and efficient weapon, and if you're in range and aim properly, it never misses.
Also, show me a video of you using that tactic and "pirates never touching your shields" while using the photon cannon.
Watch these poor pirates perish in a rain of photon projectiles.
As I said, I believe photon cannons to be superior in defense. Pirates never even get close to me. In close up dogfights, however, the phase beam might be better due to the auto-aim. I'm not an aggressive player so I only fight when I'm attacked and this tactic always works.