You might find that the data you’re working with doesn’t play well with some of the principles outlined above — no problem, it’s ok to break the rules sometimes. The important thing is that you test your designs against real world situations.
… typography does not hold any particular aesthetic appeal. In its inaccessibility, it resembles great music. Under the best of circumstances, it is gratefully, accepted. To remain nameless and without specific appreciation, yet to have been of service to a valuable work and to the small number of visually sensitive readers — this, as a rule, is the only compensation for the long, and indeed neverending, indenture of the typographer.