The executive and legislative branches of the government should keep to a minimum, direct interference into certain military activities such as weapons purchases and target selections. Only the military should have the right to determine which weapons it will or will not need in the future. And during the course of a military campaign, civilian planners outside of the military should not regularly demand whether or how certain targets should be struck.
Of course, the military should always be entirely under civilian control, but the proper place for civilian control and where it would be most effective would be in the areas of constructing and formulating the principles by which military plans and operations are decided, such as how many major and/or minor conflicts the military should be designed to adequately respond to, how far to go in the prosecution of a war (i.e., conditional or unconditional surrender), the use of unconventional weapons and tactics (such as nuclear weapons, torture, etc.), the execution of medium or long term military activities on foreign lands as well as deciding whether or not to use certain bases in foreign countries for certain missions. Virtually everything else should be left up to the military to decide. This will allow the military more efficient control of its resources so that it could accomplish its objectives more quickly. Proper civilian control over the big picture would make civilian micromanagement unnecessary. So while civilian control should be shifted away from the lower levels of military planning and operations and dwell mostly at the higher levels of planning and operations, civilian control would still be allowed to overrule any military decisions at any level.