What are the 10 most useful things I learned this year?

I know it's not the end of the year, but it is the new semester, and coincidentally it's been exactly 3 years since I started taking group classical guitar lessons (individual lessons didn't happen 'til later).  In fact when I started I didn't even own a classical guitar - I took lessons using an English steel string guitar my mom bought me as a generous and much-appreciated gift to encourage my new hobby.  I figured that was OK - I didn't really intend to learn "classical" guitar anyway, just wanted to learn some  basics.   How wrong can you be?

Anyway, at least in part for my benefit to hammer them home, here are some of the useful things I have learned this year -not in order of importance, just in the order I thought of them :)

1. Exercises improve a lot faster if you use a metronome.  Really.  I practiced one slur exercise for weeks and weeks on and off and didn't make any noticeable improvement until I started practicing with the 'nome - then I made more progress in one day than I had in the previous several weeks.  Why?  it made me slow down then stop and practice the movement in isolation that had been holding things up.  Which leads to...
2. Isolate difficult parts down to the smallest possible movement.  And repeat it slowly until its in muscle memory.  For some reason this is incredibly hard for me - I always want to speed it up before I've actually really got it.  Which leads to...
3. Don't move on until you can do it 10x without errors.  This can be soooo frustrating....  but it works.  I've been applying it to the parts of my pieces where I stumble most often. with  good results.  However it does require patience and I am woefully lacking in that area...
4. Improvising with the rhythm or harmony of a piece you already know can really help you learn the piece more thoroughly.  I'm terrible at reading guitar music - I memorize it way before I can actually play it, and then rarely go back to the notation (unless forced to by my teacher). I also haven't reached the stage where I understand the music I play - apart from picking out the melody line I just play the notes - I know, gotta long way to go.   However I had 3 separate nudges to do some 'improvisation'  recently (once from my teacher in a slightly different context, once from an instructional webcast, and once from folk camp).   Turns out that was exactly the number of suggestions required for me to actually try it.  Most notably I found I had to go back to the music (gasp) to find out which chords were being used and where they were, and to figure out the underlying structure. It was quite educational ;)  I ended up with a variation on the first half of a piece I often play.  I know, not kosher for classical guitar, but I'm just playing for fun so sue me!
5. Learning to sight read is a long slow process.   I wasn't getting anywhere much by using the beginning sight reading books - I know what the notes are if you point to them, but my fingers don't seem to map them out.  I think this means that I should actually do some technical work - scales in various intervals perhaps.  Helpfully, my teacher just gave me a really dastardly exercise (the first of a series, gulp)  that addresses this issue.  Maybe by next year I will be able to report progress in this area.
6. Memorization involves more than muscle memory.  I've heard this so many times,  and I truly believe it, having now blanked out on a regular basis when playing at the nursing home. Unfortunately the fixes for it mostly seemed out of my reach.  Such things as   "visualize the notation in your head" (oh right - that music I haven't looked at in recent history!), or "be able to play the whole piece through with each hand separately without the guitar."   Um.  I must have the wrong kind of brain.  Then out of left field, a suggestion from another musician (non-classical guitar player) seems to have helped.  He suggested practicing the left hand by itself but with the guitar. I thought I already had this until I tried it. Nope.  However it wasn't that hard to relearn the left hand without the aural and RH cues,  and yeah! it seems to be helping.  I have read that the conscious brain gets in the way of your muscle memory when you are stressed - so you need to learn your repertoire with the conscious brain as well as the "unconscious" one (AKA muscle memory).  Seems that learning the LH by itself even with the guitar present must get that conscious brain working -  and speaking of right and left hands...
7. If there is a part that is causing you trouble, practice the right and left hands separately.  I can't tell you how many times this fixed a problem that seemed insuperable, but somehow I never seem to remember it until all else has failed...
8. If you want to be able to play for others, you need to practice playing for others.  I've written a lot about this because it's my personal bailiwick, but my take home message is to start by finding the safest venue you can where it's just not possible to fail.  You aren't doing yourself any favors if you try but crash and burn, because that failure adds even more stress the next time around.  Everyone has a different stress-inducer  - for some it's being on stage, or playing for large numbers of people, or people you don't know, or whatever. For me it's the fear of being judged and found wanting.  Thus my low stress environments have been areas where evaluation (of me) isn't an issue: playing in a public park and for a dementia unit in a nursing home.  And I had to do it many times before the stress started to abate.   I've learned a lot as a result and my confidence is slowly building.   I'm not ready to play for a knowledgeable audience yet, such as the guitar club, and even playing for my teacher still gives me problems, but I can see the next step might be a casual open mic where the audience are not guitarists...   
9. Recording yourself is a humbling experience but incredibly useful. I don't do this enough.  You hear about 10x as much when listening to a recording as when you are playing.  Even if it's just an iphone recording. I'm making a resolution to do it more even as I write this!   And there's a reason that the teacher needs to see your hands if you are learning by Skype.  I've only ever made one video recording (on the iphone again) and it was more mortifying than humbling, but having the picture of what your hands are doing adds another dimension to what you can learn. And as a ski instructor once pointed out to me when we were being videotaped, everyone else has already seen how you ski so you don't need to worry about them!
10. Playing with others jump starts your learning. If you get the chance, join an orchestra or ensemble.  I am learning a long list of things that I doubt I would have got around to yet if not for the orchestra, such as strange exotic rhythms, keeping time (including with strange exotic rhythms ;)), artificial harmonics, percussive techniques, playing repetitions in different positions, extensive use of dynamics ....... oh and being able to play without looking at the fretboard all the time ;)  And last but not least my guitar friends :)