I have taught at the college level for 5 years and a few at high school as well. Long ago, but I did 
The problem with ‘lazy’ is that people are much too quick to attach that label to people. Before you attach that label to a student, be sure they really are lazy. Many times what you think of as lazy is actually confusion and/or lack of confidence. Especially in Math, which is what I mostly taught.
There are also people that appear lazy but are not really…they just don’t care about your subject. An Art student forced to take College Algebra is probably not going to put forth much effort. A good student would…but Joe or Jane Doe…not so much.
So, How did I handle lazy students?
First - are they truely lazy? If they skip classes, then they probably are. Even if they aren’t, they are beyond help. I have nothing against students skipping class…even gave A’s to some students who seldom showed. All I cared was can you demonstrate competence on the tests. If you can, showing up is not important. Few students could pull this off though.
IF a student is showing up and failing…they just might need some help. I mean they are showing uo…they can’t be THAT lazy. I had a long list of people/ex students that wanted to tutor…audio visual aids etc etc. Approach these students and try to grab them and get them going on this. Give them exactly what you want them to do.
Many people are not confident, mentally healthy people and need some guidance. They appear lazy but are not. They are just so down and out/lacking any sort of confidence that a little direction does wonders.
For people that are not lazy but just don’t care about your class (Art majors in College Algebra for instance)…push em but unless they fail miserably, give em a D. A ‘D’ is not going to fool anyone when they see it on the transcript - they will know this person didn’t learn much. However, what is the point of torturing someone with College Algebra again when they don’t care? Get em through and on with their life. It’s not like they will show up in Calculus because Calculus requires a C or better in the prereqs.
The truely lazy? Ones that can’t even put forth the effort to get even somewhat close to a D grade? The ones that rebuke the effort you made to help?
Screw em. F. Don’t give them much thought. However, they are less common then you think.