I do the standard line of infantry, artillery with cavalry at the sides and the general behind. But I always keep some elite troops in reserve. Once I find out what part of the enemy line is weakest I use the reserve troops to put more pressure on it. Then I close in for melee on that part of the line and hopefully break it. That's when I rush troops in through the hole to get behind the enemy then order the rest of the line to close to melee.