When firing all these weapons, troops should do it from positions they would normally be in. For support troops, this means from vehicles, or from the kinds of positions they would be manning while pulling guard (force protection) duty. Doing firing from both sides (right and left) and practicing rapid changing of magazines is also useful.
One of the deficiencies discovered during the Iraq fighting was the large number of support troops who had not maintained their skills with their weapons. All support troops are issued rifles or pistols. And most support units have various types of machine-guns assigned as well. Many support units had gotten into the habit of only letting the troops handle these weapons a few times a year. This has been made worse in the last few years by shortages of rifle ammunition (which is another story.) For the moment, the brass have agreed that the support troops have to spend more time using their rifles. But more than that is required. Just firing a few hundred rounds on a rifle range several times a year is not sufficient. All troops have to at least know the basics of operating the various types of machine-guns that, because of casualties or personnel shortages, they may be called on use. Mainly this means the light (5.56mm), medium (7.62mm) and heavy (12.7mm/.50 caliber) machine-guns. Having each soldier in the unit go through the drill, several times a year, of loading, firing and clearing (getting a dud round out) these weapons could later be a lifesaver. Regularly showing troops how to fire common enemy weapons (AK-47, RPG rocket launcher and PKM light machine-gun) doesnt take much time and is another potential lifesaver.