How to XP up units?

[Marquis of Roland]

Using this cheesy strategy as France on Bavaria i was able to build up 4 line infantry units to 4 chevrons, 3 Cheveux Legers to 3 chevrons, and a Cour de Blois to 4. Sadly the AI is starting to become more clever and will prioritize shooting my elite troopers instead of green line or my throwaway militia (they WILL pivot their line to go after my elites even whiling eating raking fire from my lesser units). Sometimes i'm forced to charge my suicide militia and go Longshanks Braveheart style shooting at the melee mass with my militia stuck in the middle (use up the Irish! heh).

AI going for your elite guys is probably the best thing that can happen, because then you'll know where to make a kill zone that the AI is always going to walk into

[loony]

In my older stacks I have most units with 3 chevrons and 3-4 with 4 chevrons.
I don't do anything specific to xp my units, if I have numerical inferiority, i make them shoot against 3-4 enemy units and then kill the enemy with explosive shells, and a charge from flanks.

where I have superiority I do the volley - charge trick.

and most of the dying is done by my militia, least - light infantry. I place militia in front to begin the shootout, line infantry and cannons behind them to form a battle line and light infantry on elevated slopes so hey shoot from behind at the same guys my line is shooting at.
oh yes, and i do use cavalry as primarily a "router" force, i.e. only after the enemy ranks are somewhat thinned.

all of the above on H (VH is crap; e.g. 10 regiment horses kill 160 people line infantry... don't lose one bugger.... crap)

[Prussian to the Iron]

playing anything above medium gives the A.I. enormous stat bonuses, to the point where a unit of line infantry won't be able to beat an enemy dismounted dragoons.

my advice is ot play with medium for battle dificulty, and campaign VH. that way you have all the same challenges, but battles make some sense.

as for upping xp, heres how i did it with marathas:

i my army was attacked by an anemy army, so i fought. i won, and the enemy was destroyed so i now only had to capture the militia-only guarded city. i for some reason only sent 3 units to fight. these 3 units were bargir musketeers that bore the brunt of the last battle, and now had a chevron each. the enemy sallied forth and attacked them, and i surprisingly own the battle. because the number of militia defending any city is for some strange reason 880 every time, and i had only around 3-400 men, they immediately went straight up to 3 chevrons each. basically, just take enough men that it adds up to about 500, and besiege a city. when the militia sally forth defeat them and you should have a bunch of xp. if you want you can make the city revolt and rinse and repeat until you are as high as you want. note though that you will probably have to merge units and revolve some units in and out of the combat zone to keep the XP.