I just spent some time (as in several hours) watching YouTube videos of some of my favorite guitarists playing live, mostly because I was bored and needed some music so I could study, but I did learn a few things that can hopefully help improve my guitar-playing speed and overall technique.

1: None of the guitarists I watched used any more tension in either hand than needed for either playing the notes cleanly or for really getting the feeling they wanted out of their guitars.

2: None of them seemed to let a bad note bother them.

3: They all just had fun playing, even if they messed up a Riff or a Solo

And what exactly are my mistakes in relation to this?

1: I usually use way too much tension when playing things, instead of carefully finding out where to place my fingers for best performance (not good). Especially with Barre Chords.

2: I tend to stop a solo when I hit a bad note, and try to get that note right before continuing the solo (very bad, I know).

3: If I mess up enough times on any song, I just start to find it boring, even if it's one of my favorites, and at least once has it kept me from actually bothering with learning that song. I've recently started trying again, this time with more success.

At least I now what I have to focus on when I get the chance. And as my teacher (not guitar-teacher. Tech-School-teacher) keeps saying, the first step towards fixing any problem is to find out what the problem is. And I think that applies to pretty much anything. I've found out a lot of the things I'm doing wrong, and indirectly, I've found out how to fix my guitar-playing.