Here's a pretty cool lesson video posted by Bad Guitar in April 2015.
Bad Guitar's motto is "no talk, just licks," which is actually kinda refreshing.
Anyway, in this video, which has already garnered more than 1,000,000 views, Bad Guitar presents what he calls "5 rare guitar techniques just for fun."
Here are his five techniques in order, complete with his own explanations (with a bit of editing; for the unedited version, head here). Before we go, we suggest you follow Bad Guitar on YouTube. He posts some pretty useful stuff for sure.
1. Picking hand bending (0:19): Not an ultra-rare technique but something pretty cool for people who prefer fixed bridges but still want to do some whammy bar tricks. I think Zakk Wylde does something similar, so you might want to check out his technique.
2. Playing harmonics by resting a finger on top of a string (1:23): There's a pretty common trick where you play a repetitive legato pattern and slide your finger/palm along the string to get different harmonics. This is exactly that, but instead of playing harmonics randomly, the finger rests on a string and the fretting hand plays legato patterns to bring out specific harmonics.
In the video I rest my finger on the 12th fret and play a legato pattern using the open string (12 frets below the resting finger), the fifth fret (seven frets below) and the seventh fret (five frets below). Pretty cool for spicing up your tapping runs too (2:33). That's what I mainly use it for.
3. Picking and tapping combined (2:35): This is for those of you who don't mind playing dirty. The dull corner of the pick frets the string on every stroke and every time the pick is past the string the note fretted normally is ringing. So with one down-up motion you'll get four notes. I'm sure there are people who use this technique, but I've never actually seen anyone do this so if you do this or if you know someone who does this, let me know. I'd very much like to hear how people use it.
4. Dissonant wobbly sounds using slip harmonics (3:34): Not sure if this impresses normal people but for someone who has been playing a long time this can be almost like a guitar magic trick. Play a natural harmonic and instead of lifting your finger up, slip it behind the fret. This allows you to bend harmonics. Do this with a natural harmonic also ringing and you'll get some perfectly awful dissonant wobbly sounds. Do this with the right notes and the beat frequency ends up sounding like an extra note, that goes down while you are bending up (3:55) and vice versa. In the video I'm playing a natural harmonic on 4th string 5th fret and a slip harmonic on 1st string 7th fret. (BTW, you can do this with generated sine waves too if this phenomenon is something you are interested in).
5. Playing with a drumstick (4:16):: Of these five tricks, this is the one I use the most. Learned this idea from a Johnny "Guitar" Watson video. I mainly use it for screechy violin-like sounds in the background of songs. I even play melodies with it occasionally. Sometimes I lift the string up so that it doesn't hit the frets (4:36).