If you don't have that critical target in your sights, or you don't know that you can take a direct hit, then evade.
Evading involves a pretty complicated series of decisions you have to learn to make by reflex.
If you have better maneuverability than your pursuer, try a Tight Loop, Kickstop, or Fishhook. If you're hurt, though, and prefer not to mix it up, you can try to evade with a Turn-'n'-Kick or any hard turn... if your acceleration is better than the enemy's. If it isn't, try any number of hard turns and tolls, and hope for the best.
If your puruer has better maneuverability than you but you have superior acceleration, try a Burnout or a Hard Brake... and prepare to be very accurate with ship's weapons.
If your pursuer has better maneuverability and acceleration

--------- 5 Years Ago ---------
Terran ground forces launching an attack on a fortified Kilrathi colonial position are routed by unexpected Kilrathi fighter-craft support. The Terrans quickly reform and advance back into Terran space, their lightly-armed transports pursued by Kilrathi warships. TCS Tiger's Claw is detached from its previous station and sent to the Terran fleet's path.
Tiger's Claw fights a delaying action, subsequently called Custer's Carnival, to allow the Terran fleet time to reach Terran-controlled space. Though swarmed and badly damaged by Kilrathi fighter-craft, the carrier occupies the Kilrathi forces until the Terran fleet reaches safety. The Claw is able to limp back into Terran space, though three-quarters of its engines are destroyed and half its pilots are listed as casualties.
Subsequently, two Gold Stars and numerous other medals are awarded to Tiger's Claw personnel, and the carrier spends six months in spacedock being repaired and refitted.
than you, you have a problem. If you want to make it a slugging match, try a Sit-'n'-Spin or Turn-'n'-Spin. If you're already hurt, try any sort of evasive maneuver you can - zig-zags, hard turns, and rolls in a succession of different directions... and pray, because you're going to need some divine intervention.

Last Notes
There's no sure way, no sure tactic, to keep you alive on a combat mission. You may be good, but so are the Kilrathi. Somebody's got to win, and somebody will probably die.
The Book, sneered at by up-and-coming aces, is nothing more than a manual which teaches you how to slant the odds in your favor. It says nothing more than this: "Protect your wingman and he'll protect you. Lean these tactivs and they'll improve your chances." That's all.
And just remember: You're not the only one who wants your chances to be improved. Your wingman does. Your commander does. Your family does. Ultimately, the entire Terran Confederation does. Because if we fail, our people and our planets will end up "protected" by pilots who proved themselves better than us, fliers who showed they could beat us: The warriors of the Empire of Kilrah.