Mausoleum is extremely wide, and is the first to feature the Torque Bow, on one side of the map. It has a round walkway in the center, where the Boomshot Grenade Launcher and two frag grenades spawn. On the other side of the map, opposite to the Torque Bow, is the Longshot Sniper Rifle. Both teams start out at the top and bottom. It has a lot of cover, having the tombstones.
The most important thing here is to stay with your team, even if it's just one person. A single person will get shredded really quickly unless you're really lucky. The round hub-like area is guaranteed to be where the fight is. In this point, communicate with your team and have them concentrate their fire on one person, even just blindfiring, to keep the enemy distracted. Then, chainsaw or shotgun the person from behind. You may also want some heavy weapons support, so go for the Boomshot.
One person can still make a difference. However, he will have to use "Green Beret" tactics and mainly ambush his opponents. Not too hard, considering the many swirls and debris that make up the map.