Time spent on tactics is always well-spent. You may have heard the maxim, “An hour a day keeps the blunder away.” Solving tactical problems is always useful to maintain alertness and sharpness and should be an important and regular part of every player’s study program.
In a perfect world, perhaps the chess student should ideally break up his daily study session into several different areas: say, one hour of tactics, followed by one hour of endgames, etc. There are some arguments in favor of this approach. The student who thus organizes his time does not neglect any one area. This scatter-shot approach to learning is time-tested by the standard program in schools which has the student moving between several classes on widely different topics during the course of a single day.
However, amateur players are not likely to have several hours a day available to study chess: instead, they are likely to have only scattered hours and half-hours here and there, time stolen from other activities of daily life. They may even have to squeeze in their chess study while riding the train or bus to work. (This is true not only of chessplayers. The writer Andre Dubus III, author of the bestselling novel The House of Sand and Fog, which was made into a critically acclaimed movie, told me he wrote some of the book sitting in his car in his driveway, during odd quarter-hours and half-hours between his other tasks.)
For most amateurs, it may be simplest in practice to follow a program in which they start and finish an entire book and then move on to the next book, without jumping around constantly by working through a few pages in a tactics book, then a few pages in an endgame book, then a few pages in an opening book, etc. That way lies madness, and I am not sure how much good solid learning would occur. Perhaps it is better for them to start a book and go all the way through to the end, covering the material from start to finish without interruption as the author presents it, and without multiple confusing detours into other books.
I suppose, if you do have time available to study chess while riding the train to work, you might want to allocate that time solely to solving tactical problems, for reasons of logistics; reserving other studies, that require a board and uninterrupted reflection, for quiet time at home.
Probably no chess training program is perfect, let alone an amateur’s self-directed program. A perfect chess training program, if it exists at all, is likely to be one that is prescribed by an experienced chess trainer who knows you and your individual needs well. If you have access to such a trainer, good for you: most of us have to do without.
But even a perfect chess training program, if it could be devised, would only be as good as its execution. Perhaps there is an analogy to exercise programs. Even an ideal exercise program would be useless if you failed to follow it—perhaps because the gym was inconveniently located, or you found the routine boring, or the fees were too expensive, or the program took too much time out of your day, or the effort left you too tired for other activities of life. Therefore, as experienced fitness professionals understand, the best exercise program for you is the one you will actually follow!
Similarly, the best chess training program for you is the one you will actually follow—because you enjoy it, it suits your schedule, and the financial burden is manageable (books, software, teacher’s fees, tournament expenses).
So don’t overthink your chess training program. Make a realistic, even modest plan that you believe you can follow. Any plan will suffice, as long as you actually do follow it. Then follow it faithfully, making sure to log your work accurately, at least long enough to see where it leads you. As a guideline, one Russian trainer suggests at least six months is required before your chess work will show up in your game results. You might resolve to follow your new program for six months, then reevaluate. Rather than continually chopping and changing, pick a direction and follow it. Any direction is better than no direction: at least you are likely to get somewhere, and it will be a different place than you are now. Of course, if you are happy with the results you are already getting, don’t change anything!