Is it just me, or do the ninja of Naruto never seem to use their jutsu/abilities to their full potential?
Example #1: Genjutsu.
Widely considered by fans to be useless (with the exception of Tsukuyomi) due to the fact that a person caught in a genjutsu can resist in a number of ways (stop chakra flow, inflicting pain upon self, outside intereference, etc.).
Whereas this can be a significant flaw, note that all these 'escape' methods are only viable if the target realizes they've been 'caught'.
Apparently Naruto ninja have never heard the word "subtlety", and think that all jutsu must be used to directly kill the enemy. Personally, I would have thought the most obvious application of illusion is not to fry your opponent's brain, but to cause them to misjudge their environment (e.g. mess with perception of distances, or cause yourself to appear in a slightly different place than you actually are; whenever the enemy would hit your illusory self, just shift the illusion to a different place, and the enemy would most likely just assume you are damned fast).
As a matter of fact, the only not-obviously-supernatural genjutsu we've seen used was by Kakashi, during the first bell-trial.
Example #2: Byakugan
The basic abilities of the byakugan are a) ability to see through physical obstacles, b) 360 degree field of vision, and c) ability to see chakra.
Which of these has the most obvious combat applications? While the highly specialized combat techniques that c) allows are certainly powerful... for an effortless, no-training-required, out-of-the-box advantage, a) wins hands down.
To put it another way, it is impossible to blind a byakugan user. It is not impossible to blind a normal ninja (via mist, smoke, flares, etc.). Thus, for a byakugan user, it is highly advantageous to introduce some sight-inhibiting element when fighting.
I can understand that it's not always viable in every situation (i.e. when teammates are involved), but why does it seem this is never done, at all?
Example #3: Kagemane no jutsu
Probably the most interesting technique we've seen, kagemane no jutsu is almost never used with direct attacks, presumably because the opponent would mimick and attack the user.
Unfortunately, there isn't really much support for this assumption. Once the kagemane is successful, there is no evidence to suggest the enemy automatically 're-orients' to face the user, thus kagemane used from behind the enemy should effective prevent any retaliation, leaving the user free to stick them full of kunai (as kagemane is not a genjutsu, inflicting pain should not be an issue).
Example #4: Vanilla bunshin
Every ninja knows this technique, yet we almost never see it used. Is it really so useless? I don't think so.
Naruto in particular would benefit greatly from mixing a few regular bunshin with his kage bunshin. Why? Well, while a kage bunshin is solid long enough to absorb the full force of a punch or kick, a normal bunshin is completely immaterial. Hence, an enemy attacking a bunshin expecting actual contact would be very likely to show an opening during the follow-through portion of their attack (i.e. by overextending themselves).
Well, since this is Naruto we're talking about, it's understandable that he might not have given this any thought, but it's still surprising that seemingly no one ever bothers to use this jutsu outside of the ninja academy.