I can give my personal opinion on how to make good solos... How I did it. And how you should not do, how a friend of mine did it...
I learned myself to play along other bands songs, like Iron Maiden and Judas Priest when I was 11 (now 22). I learned with ear, I didn't even know there was notes or tabs. Still cannot read tabs or notes
I know nothing about theory.
This is the SLOW path. It takes a fucking while before you get somewhere, but for me personally, I think it's a good way. You don't rely on those fucking technique lessons and shit... That makes you limited. If you learn how to play ACTUAL solos from real bands, and Adrian Smith from Iron Maiden and Glenn Tipton from Judas Priest are the best "teachers" you can have. All there solos are different and good sense for melody. Best is to start out with Adrian solos, they are mostly easier. Glenn Tipton is diverse and can go to fucking insane shit I still can't even do, but I don't even aim for stuff like that anyway...
That's how I did it, and I could admit I do some quite good solos http://www.youtube.com/watch?v=peWXh9waPfA
(solo starts at 2:49)
This is from a competition I got third place from... I very rarely use any "techniques" that are being tought out in lessons and shit... Interesting solos are done in a unique way instead.
Note that I am self learned with ear and know NOTHING about theory.
Also, I'm not a very skilled guitarist at all, I can be fucking sloppy at times.
So basically what I think is the wrong approach is that you actually learn every technique and shit you can find. Of course you should do some of that as well, but the problem is that you probably learn the exact same shit as everybody else and it will be harder to develop a more personal style.
ALSO, if you don't progress for simple stuff you probably end up like my friend. He is WAY ahead of me with technical playing, but his solo compositions unfortunately often sound awkward, he's out of tune (and not because his guitar is!) and misses chord progressions and shit... He can have a hard time improvising as well. And that is all because he is limited to his techniques.
But I have lately begun to be a "teacher" for him and he has said next time he makes a solo he wont use ANY technique he knows and THAT IS IMPROVEMENT for me.
There are examples of wellknown artists who cannot write a fucking solo without being a parody of themselves as well... YNGWIE MALMSTEEN and Kerry King even tho Kerry at least makes solos that does not even have to be good. Yngwie just repeats the same shit over and over again.
I can make Yngwie parody (even if not as precise of course), Kerry parody, hell I can even parody my friend! I know every fuckign techniqe he uses ALL THE TIME so it's very predictable once he starts soloing.
But you cannot really parody Adrian Smith or Glenn Tipton, because they always makes totally different solos always crafted for the song, and not a showcase of what techniques they can play.
In conclusion... You can take a shortcut and learn everything everybody else have learned, which is okay and makes you a precise and fast player early on, or take a longer road to interesting solo playing.