A few simple tactics:
If you are ambushing somebody, make sure to have a splash poison potion (I or II), as they ignore armour, which can be extraordinarily helpful against opponents with enchanted armour. It does not kill them, though, only brings them to half a heart! This tactic is also useful is you are turning round to face a pursuer.
Enchantments are also an excellent way to defend yourself and increase your attacking potential. A fire aspect enchantment on your sword is a great alternative to a poison potion, but it can be harder to find as it isnt a guarantee that youll enchant it on the first go. Make sure to also keep up your defensive enchantments, though!
If you are currently in a melee battle, try and circle+jump around your opponent whilst spamming your left click. This is a common tactic though, so expect your opponent to do it as well! The jumping ensures you will get critical hits, which can get you up to 50% extra damage! Try and switch directions often though, as it is easy to counter by simply hitting a bit in front of where you actually are.
It can be a lot easier to kill them with a bow, which negates the danger of the enemy quickly wearing down your health, unless they are a better shot than you. You can shoot them a few times before entering melee combat, as they will enter with slightly diminished health. If you have a fire aspect enchantment on your bow, then they will enter slowly burning to death. It is also a great way to finish off a fleeing enemy.
If youre on the defensive, remember to block/parry! You simply hold right click facing an enemy, and the attacks only do half damage. This does not decrease durability on the sword.
Strafing: Do quick circles around your enemy while focusing and hitting the target at the same time.
Pots:Bring strength 2 for every fight to get an advantage, bring speed 2 for an edge on your enemy, or a quick get-away.
Weapons/Armour: Do not put any enchantments on close range weapons other than sharpness, other enchantments will weaken the power of your sharpness.Bows do not have the same qualities as swords and axes, so go all out on the enchants. Go for protection 4, unbreaking 3 armour. You could use thorns to cause your opponents armour slight damage with every hit they take, however with protection 4, unbreaking 3 and thorns you cant repair your armour in an anvil.
Crits/jumping: Do not use this tactic ever, you take more knockback in pvp (you dont want to be knocked back in pvp) and you do more damage, but your opponent also does more damage to you, so its counter effective.
Dont get Shot: If you are in pvp with a good archer, you need to dodge those arrows. Run in a zig-zag pattern to throw off their aim.
Gapples: if you dont know what a gapple is, its an enchanted golden apple. If you have them, use them. Dont waste gapples and exhaust your resources. If you have a decent gold farm dont be shy to use your gapples.
Hope I helped ~Sky
