The you can do some of these in "White Box Laboratories".
After you've exit the elevator, wait for the doors to close. Peek under and mark the 4 targets in the room. Then, enter the room on the right side of the Weapon Stash and go through the right open window. Move along the ledge and at the 2th window grap the guy in front of the window (gives you also a point for Grab from Ledge). Now you can use an EMP and M&E the 4 other targets which gives you 2 points for Mark Proficiency and 4 for Behind Closed Doors. Reload and redo until you get the Behind Closed Doors complete.
Since M&E on stunned targets often count as 1 point, there is a faster way: do the same as writing above, but instead of M&E just shoot and kill. Don't forget to use the emp before you drag the guy out of the window. Gives you 5 points in a row.
You can also do 3x Frag Grenade at the elevator. Wait until the doors are closed and trow a grenade at the right door, aim just a bit above the handle. When it explodes, it kills the guys behind the door, if you trow the frag right. As a reference for a good kill, if the frag destroys the door completely, you get a point. You can do the 3x Frag Grenade fast because it's basicly load, trow, wait for explosion, load. Same methodes goes for the challenge with the remote detonation