There are a few teaching strategies I've come up with - not invented, but rather discovered - in my time as a tutor that seem to keep the student both interested and focused. Of course, these may not work for other subjects. I teach language, a beautiful art in and of itself!
One strategy is to start with the building blocks of language- the atom, or proton, or electron, or quark (I suppose this is now the smallest accepted particle of matter): vocabulary, both nouns and verbs, with pictures. Then sentence structure, and finally grammar.
With the student, I build the language with them as one would build a model airplane. The key is to keep them involved. Language instruction in any kind of lecture format simply does not work.
The other strategy is something I use with more advanced students, or even ones with some basic foundation of a language. Starting with a text in Spanish - be it Unamuno or Cervantes, we start reading together. Throughout, we stop at vocab the student may not have encountered previously, in addition to verb conjugations and grammar. For each, we deconstruct and, using my own tools and worksheets, we delve deeper into learning those concepts. By the end of the book, the student has advanced, without question.
In terms of keeping a student engaged, I find that my attitude toward the subject is oftentimes mirrored by the student. I try to be as energetic and impassioned as I actually AM internally.
Games are fun and keep them entertained, but I find they also serve as a distraction. Depending on the age and skill level of the student, games can be useful as well.