I'll tell you something that helps me. This will probably sound stupid but anyway. I try to stay a hard target and always close to cover and if im out in the open i try to keep being a hard target with alot of eradict movements like jumping and going to prone and all that. A good comparison would be movement in boxing. A boxer doesnt stay stationary, he uses head movement and such to stay a hard target lol.
Ive had times in Dom when I was capping a flag by myself and someone tried to kill me but coudlt because I was jumping all around and going prone, just basically going nuts cause of course I had a shotty and they were way outta my distance. Its actually pretty funny when it happens, I would love to post a vid.