Start hiring mercs, any kind of heavy cav will be helpful as well as any halbs/bills you can find.
beware that on certain borders you can fight a bridge battle so that will help immensely when facing their panzers.. err, MHC.
Make a solid spear wall and keep fast, light cav at hand for the pesky HA and ranged inf.
Watch out the final part of the battle, i've got my spears decimated by their pesky naphta trowers while i was chasing some horse archer unit...

Finally, jihad spam can help you immensely if you can spare the money for it... Multiple jihads can give you a quick influx of good level troops that can be extremely useful.