Every battle I play, end up the same, a couple of my cannons destroyed. When off campaigning in Spain, that's just not acceptable, but since I haven't got access to Horse Artillery yet (and I doubt that it would make that much of a difference, limbering taking time and all), I can't get them away from the front lines quickly enough.
With battles that have a sizeable hill, it's alright, but I am, and I always have been, a defensive commander, ever since Rome, and in Napoleon, that's a large problem when fighting straight up line-to-line battles without any hills at all.
Usually, I position all my artillery on one flank, with a unit of Line Infantry and my cavalry behind (Light Dragoons for the time being, as long as they're not used), and then the thin red line next to them, with two groups behind for reinforcing where needed, and my light foot somewhere off to the flank.
This often results in an early melee charge against my poor cannoneers (Cavalry usually isn't a problem due to the line infantry picking them to pieces with a volley), and voilį, a cannon or two lost.
I rarely use artillery the way most of you seem to use it - soften up the enemy for the charge, I mainly just point them in the direction of the enemy and let them go on until my superior line infantry can start shooting, so the loss of cannons isn't crippling to my war effort, but I've found that shooting at people often make them attack, which means that all I have to do is hold the line, step forward after the first enemy volley and turn on fire at will.
The real question is, as the topic states; how the hell do I protect my artillery without any terrain for them to fire from?