Given the advance in robotics and IA, we have to foresee a future where most jobs will be overtaken by robots, whether they look like humans, or not (have you seen the latest Google Voice AI presentation?)
The question is not really what jobs, because I think that it will happen to all jobs at one point, but when. And the "when" is already "now" for a lot of low-pay jobs.

I won't go into too much details regarding how UBI could be implemented, because I am not knowledgeable enough and there are much more brilliant people than me thinking about the subject.

However, there is one thing I'm absolutely confident in: if your survival is covered by some form of regular income, what would you do?
First, I would include in "survival" the following things: food, housing, internet. Now, if all of that is covered, what would you do with your time? Those not favor in UBI will often say that a vast majority of people would do "nothing".
I, however, strongly believe it will allow people to explore, try activities/jobs that they could not before because they had to work all day.
And I think this is the way to go for humanity: achieve full potential for everybody, in whatever discipline they choose. And wrong choices should totally happen.

One book I often refer to, by the great Arthur C. Clarke, Childhood's End, explores this idea of having everyone be able to try whatever he wants.
One of my favorite books.