for the heck of it, lets catalog our combat tricks
1.Strangling
Wrestling someone and strangling them causes instant unconsciousness (assuming they need to breathe). If you're fast you can catch, choke and strangle someone unconscious before they can get an attack off, leaving them helpless. It's a great way to deal with armored foes or overwhelming odds.
2.Power leveling fighting skill for better aimed attacks.
This is best done right away to get the full effect. Get a mission to kill a bandit and go to the camp alone (don't worry about being overwhelmed, the number of bandits that spawn is based mostly on the number of people following you). Kill all except one person and then strangle them unconscious. Set your combat preference to "close combat" and then just keep running into the enemy, stepping back and then starting again if you ever start to strangle him. This causes both the wrestle and fighter skill to level up extremely fast. You can get to legendary in a matter of minutes like this.
3.Dual wielding for more attack opportunities.
Wielding two weapons at once increases the number of attacks you can perform (swords allow for 4 different attacks each(stab,slash,slap and bash), so dual wielding two can allow for 8 ) This seems to increase the odds of random combat opportunities (the blue exclamation marks). With legendary fighter skill, superhuman agility and professional swordsman skill it's not uncommon to have 3-4 opportunities with each attack.
4.Aim for the hands.
While using a blade (ax, halberd, sword, dagger) it's a good strategy to aim for the opponent's hands, especially the one holding his weapon. I've found that even glancing blows can cause them to drop their weapon, rendering them much less dangerous.
5.Blades are better
Kind of a personal idea but in my experience blades are just plain easier to kill with. Pikes and spear are alright but hammers and maces are pretty crappy. Blades simply allow for quicker and easier disarming, more grievous, bleeding wounds and quicker movement speed (they encumber you less then blunt weapons).
6.Dealing with armored opponents
Armor is a real problem, especially if it's made of a higher quality metal then you're weapon. The easiest way around this is wrestling, either pulling the armor off or strangling the opponent unconscious and delivering a swift kick to the head. Blunt weapons seem to do more damage through armor then bladed ones, so a good punch to the head is probably a better idea then a slash. If you can't get the armor off, try aiming for unarmored bits. The hands and feet are rarely armored and damaging them can quickly undermine your opponent's ability to defend and attack.
7. Spill the guts
Spilling an opponent's guts isn't the nicest way to kill them, but it is an effective way to do it. Opponents with spilled guts will always eventually bleed out, and the act of spilling seems to increase hit chances for a few moments. One of my favorite combos is to cut off the weapon hand/arm, spill the guts and then decapitate.
8.Make them come to you.
Charging into battle is all well and good, but waiting and letting the enemy come to you is often a better idea. It forces them to come from a single side and usually lets you get the first attack in. If out numbered the best thing to do is usually to keep walking backward, separating the group and attacking with quick, blows before dodging away again. Combined with good speed and some strangling tactics you can slaughter dozens of people without much effort.