One of the most important and imperative things you can do as a performer in the digital age is to watch your show the next day. It is so easy now to set up a camera in the corner, run a cable to the board and BAM! you can actually see your show from the other side of the stage.
When I was, I dunno, 15 or so, I was hanging around at a Sam Ash in New York trying to play with and learn from everyone that came in. I'm sure I've told this story before, but you could go in, grab a guitar and plug it in and start playing blues progressions. Some bass player over in the corner would join in, somebody would fire up a keyboard and open the door to that room; same with a drummer or a conga or a horn or another guitar guy. I'm telling you it was something. We just hung around and played music all the time. There were days they were lined up in front, dancing on the sidewalk.
There was a cool old black dude that showed up once in a while in a beat-up Mets cap and a leather jacket. He was a bass player that had played all over the place, with all kinds of cool bands. He and I would often play when no one else was around. He worked in a hospital at night and hung around the park and the Sam Ash in the daytime. He taught me so much, but one of the tastiest tidbits was The Autopsy. That's what he called it. Record everything, then dissect everything to find out what happened.
He told me to beg, borrow, or steal a reel-to-reel player and record everything. Every rehearsal, every show, every practice session, performance or lesson. I did. I still do. I actually still have that old reel-to-reel and it still works. Now though, it's video at 1080p with CD quality sound.
Go kill a gig and record it. Then, the next day, while it is still fresh in your mind, listen to it and take it apart. Get the whole band together and some beers and pretzels and listen to it. Be thick-skinned and brutal with each other. Find the timing errors and bad notes, the miscommunication on the ending, the harmony that is not harmonious. Hear yourself as the audience hears you, where left is right and right is left. The room is reverby and gets a bounce off the hard floor. The football game in the bar wafting through as two guys have an argument on the dance floor and the drunk girl drops her drink. Hear your whole sound and hear your single notes and drum hits. Critique each other and be honest. Be specific: "I like that, I don't like that;" "Man, your lead solo should be tasty there, not a mouthful of notes." Find the things that need fixing and fix ‘em.
It's so easy now. You kids, get off my lawn. I can, and do, record a 2-camera shoot with room sound on one and board sound on the other and can watch it in the car on the way home. How cool is that. You can crank out videos too. When the waitress walks in front of one camera you might just have a shot to cut to on the other. More importantly, you get to see your show as they see you. I set one camera at seated-person height somewhere out in the crowd and use a real microphone not the camera mic. For my solo show I have one low in front of me zoomed in on my guitar and it gets plugged into the board. I can record in stereo so I use my mixer to pan my voice a little heavy left and my guitar a little heavy right. That way you get to do post-production audio mixing to fix bad sounds and make your videos sound good no matter what happens at the show.
I try to position the other camera and mic where it might catch some crowd and crowd sound. If you leave them rolling sometimes you get great honest feedback recorded as well. Stuff that you might not hear while playing you can hear when listening.
So if you set it all up, you have left and right mics for room sound and applause, and a vocal-heavy track and a guitar-heavy track to mix with the video. You could do this with a couple of smart phones. If it's just for you there is no need to go nuts. Just record everything and be brutally honest with yourself in private.
It'll do wonders for your stage presence; it will up your game and make you play better, tighter. I dare say if you're anything like me it will change your life. That old guy in the Mets cap that liked to play Wes Montgomery songs with a pimply-faced little hippie in the back of a music store was a genius. He would love the age we live in. I'd love to play with him now if only I could... wait... I have a tape.