Step 7: Minimalism
O'Toole's Commentary on Murphy's Law: Murphy was an optimist.
Logicaly, the less stuff you have in the feild, the less could go wrong. The above pictures are extreme examples of over loading or overmodification. Its best to have as little as you can because any thing you have can impede your funtionality.
Sometimes you just gotta ask yourself: Will it really help? Does a laser really do any good? Will this flashlight help enough to offset the increased likelyhood that people will see me? Will a 8x zoom scope give me anything but tunnel vision?
It remains a fact that the interaction between gun and player is the single most important factor in effectiveness and accuracy.(no matter whats bolted to it) Learning to shoot you gun by feel will probably do more for your accuracy than a spanken new ACOG.
Also consider if you really need a side arm. If you run and AEG, probably not, but if your one of those hard core sniper guys, play long sceneraios, or are using an experimental and untested gun it might be worth the weight.
The pictures are pretty extreme (both were actually a joke), but you get the idea.