You do them in batch, like kicking goals in soccer or shooting hoops in basketball.
For a beginner, you can do 10 problems in a batch. Write down answers if possible (also practice to name the squares and to write notation), then check against answer sheet if there is one. You will slowly increase it to 20, then 30 and 50.
For an advanced beginner (e.g., U500), you begin with 50 problems in a batch, quickly increase to 100. You do one batch a day for a week or two.
For an intermediate players, you start with 100 problems in a batch, then increase to 150 and 200. You can do some stress test sometimes, do as many as possible until you feel headache. Don't do that often because it will be counter-productive. Again, repeat your batches for a week.
For beginners, you strive for correctness, trying to get above 90%. For experienced players, your focus is speed.
You don't need to do this kind of training for longer term. One to two weeks at most at a time. Repeat it couple months later.
Chess for Beginners: Elementary Checkmate I
Chess for Beginners: Elementary Checkmate II