If you decide to go all-Khergit, and perhaps 'historical' in its composition with the 'pure' horsearchers and lancers being around 7:3 ratio, then you'll be spending a lot of time with the battlemap screen.
* The basics is to first put your entire army at the "follw me" order. You lead them on and usually the moving formation more or less resembles a column formation.
* Circle around the entire enemy army counter-clockwise without ever actually engaging, and keep peppering them with arrows. Ofcourse, you don't necessarily have to always move your army at the fastest gallop. All you need is just enough room to keep away from melee, but close enough to really land shots.
* Using the new Warband feature, you can recategorize your army into two groups, such as "Lances" and "Horsearchers" - in which case, you can envelop the enemy army front and back and circle it - it is a bit more difficult to command two groups in this manner, but it does help raise the kill count, since at least half of your volleys will be landing without being blocked by a shield.
* If there are cavalry in the enemy army, you can command your army to keep move around in the same fashion via the battlemap command, and then personally drive your character to in-and-out skirmish, until the enemy cavalry actively targets you and start to make their move - which, in that case, you run back to your army, set either your lancers only or the entire army to a "charge" - which will soon envelop the cavalry that followed you and deal with them.
* If you see your army spread out too much in the battlemap screen, pick a certain place and command them to move there - which will rally them into formation again. Rinse and repeat the process until either you dropped enough enemies to attempt to engage in melee, or, until the enemy army breaks formation.
* Try not to engage crossbow-heavy armies such as the Rhodoks. They hurt.
* If the enemy uses a long and thin single-line formation, put your army on "follow me" instead of "charge", and then drive into into their formation and break through. Remember to spread your cavalry out before the charge - a closely packed cavalry may seem like more momentum, but in M&B, if the first few cavalrymen are stopped then it becomes a disaster when cavalry are packed too tight.