Here some resources to help you out:
In the 'Stan where fought in the mountains mainly, concealment for our snipers has a must but we hardly used ghillie suits. In Iraq most of our guys shot from buildings or other concealed positions. It really depends on the missions and the location. You have to be ready for anything and everything. We own the night.
Here's the standards to be one in the USMC:
United States Marine Corps Enlisted Job Descriptions and Qualification Factors
8541, Scout Sniper
Scout snipers participate in activities designed to deny the enemy freedom of movement by shooting enemy leaders, crew-served weapons operators, radiomen, observers, messengers, and other key personnel with single, well-aimed shots. Scout snipers also engage vital material targets such as command and control equipment, air defense radars, and missile launchers, which require precision rifle fire to neutralize. Scout snipers also provide close reconnaissance and surveillance to the infantry battalion.
(1) Qualify as an expert rifleman.
2) Possess all the essential qualifications and capabilities of an infantry Marine.
(3) Successful completion of an approved Scout Sniper Course at Quantico or at the 1st, 2nd, or 3rd Marine Division.
(1) GySgt to Pvt:
(a) Supports combat operations by delivering precision fire on selected targets.
(b) Establishes concealed sniper/observation sites from which targets are analyzed, engaged, and information gathered.
(c) Uses map and compass for day or night land navigation.
(d) Operates and maintains weapons and optical equipment employed by the scout sniper team.
What it takes to be a Scout/Sniper:
Books (gotta read to be professional):
Hogs in the Shadows: Combat Stories from Marine Snipers in Iraq (Hardcover)
by Milo S. Afong (Author)
Ronin: A Marine Scout/Sniper Platoon in Iraq (Hardcover)
by Mike Tucker (Author)
To Be a Military Sniper (To Be A) (Paperback)
by Gregory Mast (Author), Hans Halberstadt (Author)
Ghosts: Marine Snipers in Iraq (Hardcover)
by Charles W. Henderson (Author)
The Sniper at War: From the American Revolutionary War to the Present Day (Hardcover)
by Michael E. Haskew (Author)
I hope this answered you question better vs. 'they kick azz or it's classified man!'