Once one has solved a few Sudokus (or, depending on the person, a few dozen or a few hundred), filling in naked and hidden singles can become mind-numbing if not using pencil marks and mind-less if you do. Either way, any sense of cleverness in filling them in is gone and the experience no different than solving a word search. Often, the rating of a puzzle is determined solely by how many singles are available at a given time, with no higher tactics required. (For example, Pappocom VERY EASY is all Naked Singles, EASY will have fewer singles at a time, some may be Hidden, MEDIUM usually has both Naked and Hidden but fewer at a time. Even HARD may have nothing but singles (fewer still), though it may have higher tactics as well. Only the Very Hard will always have higher tactics.) Singles-only puzzles are all essentially the same difficulty level when solved with automatic pencil marks. Turbo-Sudoku users will find there is nothing to do other than point and click.)
The situation is worse with harder puzzles, especially if you can't trust the rating. You might circle around and around looking for singles that aren't there -- or look for something more complicated too early because you can't stay awake searching for needles in the haystack
What I've been doing recently is loading puzzles into Sudoku Susser or SadMan Sudoku and letting the software automatically do all the singles in an instant, solving the next step manually, without pencil marks if possible, rinse and repeat. The tactic required will always be unknown -- but it won't be a single. Both apps can be set to use only the logical rules you pick, leaving the rest for you. You don't have to waste two seconds on puzzle that's just a glorified fill in the blanks -- and you'll be awake for the hard parts.
Turbo Sudoku highlights all singles and will automatically fill in all "easy squares" (naked singles) and a simple click fills in each highlighted hidden single one by one. The software is of limited use for very hard puzzles, as you cannot remove individual candidates, let alone do any filtering.
Pressing F11 in Simple Sudoku will make the next logical step and describe what it was at the bottom of the screen -- when you get to something beyond a single, you can UNDO a step -- of course, you will know exactly what tactic to look for -- a plus or minus depending on your mood. You can save them at that point, choosing to include the name of the tactic or not in the name of the saved file to load and solve later when you might be in the mood for a Swordfish, etc.