I don't know what the best way is but this is how I do it:
I remove the action from the stock (one stock screw and the barrel band if applicable.
I remove the trigger group from the reciever (two pins).
I remove the bolt (rear pin or bolt buffer).
I run a patch or two through the barrel to make it clean. Then I lightly oil it.
Then I spray the reciever down with brake clean. I give it a quick wipe and set it asdie to dry completely.
I also spray the bolt down and then use compressed air to dry it. I put a very light coat of oil on it and wipe most of it off.
I pull back the charging handle and wipe the guide rod. I put a drop of oil on the guide rod.
I normally just blow out the trigger group but every six months or so I will completely dissassemble and clean then lightly oil a trigger components. Do this in a well lit and clean area so you do not lose anything.
Lastly I clean the lips of my magazines.
Now it's ready to go back together. simple as that.