Conquer 1+ settlements per turn:

Logistics
-keep all units - all land units and all sea fleets
-explore: diplomat, spy, map info, to find target settlements for your armies.
-organize your forces into as many effective armies as possible each with a planned attack route -send them straight towards the towns, conquering the town and moving on to next as quickly as possible.
-depending on the situation, spend round1 money on spy(s) or units. All units of your settlement may join an army. If a unit is being built there it will arrive during cpu turn to defend, if not your undefended town is often at no risk.
-as your money turns positive, make as many armies as possible. Mercenaries, while they have a high hiring cost, are often better buys then trained troops, because the upkeep of trained troops waiting to be organized often exceeds the extra mercenary hiring cost.
-build only rarely: Troops will increase your income more than buildings.

Combat
cavalry: excellent when you're outnumbered. It's best to attack engaged or tired targets, because when they're fresh they enclose your horses.
when you double click on an enemy to charge, the cavalry need a little space. They need a little time to sound their horn. When the horn is sounded they draw the lances which deal much damage upon impact.

The instant they've impacted, or the instant before they delve too deeply into the enemy unit, double click or spam click to move them back from where they came, so that they suffer no casualties.

when an enemy unit takes heavy damage, theyll turn around and will chase you if they're not engaged tightly. Repeat the process with great frequency on the same unit, or move to another if they run after you. When you'd like to ensure a concentrated impact, form your horses into a line facing the enemy before charging.

when opposing defenders/town defenders are missile heavy - if you have a cheap skirimisher unit send him in first to take missiles which would otherwise be used on more valuable troops.

- in general, place more emphasis on maneuvering rather than missiles, assuming your army is not geared for ranged skirmishing,

Nonsiege:
front line:form the front line with a small number of infantries spaced apart, not together, their purpose being engagement. In general, line up the rest behind the leftmost and rightmost front line units in order for them to flank easily. When the battle begins you may rearrange your flankers as you target the weakest side or taret their general.
-your general, as he attracts enemies, can at times be used to direct enemies into a favorable engagement. Other times they charge the nearest unit.
-goal is to flank the engaged enemy units as quickly as possible. the more surrounded they are, the more theyll flee, and then your units are freed up to continue flanking.
-directing units: take every opportunity to pause the game and direct your units. Run the flankers ahead when the enemies show commitment to your front line, so that your flankers flank enemy front line and engage targets farther back as the front lines make contact. when the enemies switch targets, your intended engager attacks the enemy's side. When several of your units have made an enemy flee, scatter them before a charging enemy can pin all of them down.
-Outnumbered: when outnumbered, destroy any singles they send, take advantage of gaps in their advancing army to flank and kill the ones nearest you quickly. and often their units will not attack even if close to yours. For the smallest of battles: send a unit to lure away enemy units, while your remaining force eliminates one unit at a time.

Siege
Form your troops into 3 sides of a square outside the broken wall or gate. Use your general to lure their units out and then surround them.

Occupy-Enslave-Exterminate: It’s a scale. The less friendly the population, the more the population must be reduced, the farther to the right you must act. Enslaving will somewhat increase the income of the slave-receiving settlement. Barely happy settlements which receive slaves often rebel.

and the point of this is...?

Well, this is in the Guides forum, and this is kind of a guide...What's 2 and 2, again? ~;p

Thanks for that, mmadmaxx. A lot of it is common sense, but it may help quite a few newer players, I think...