A few things I learned about mistakes. Truth be told, I really hate making them, I'm often hard on myself, and I therefore do my best to keep them to a minimum.
Stay consistent and engaged in what you are doing. That’s the key for my playing.
This is one of the most important things I've learned about my playing. If I stay focused on what I'm doing, I can play as well as a classical musician. I've had many nights of no mistakes whatsoever, and while I'll admit it's not common, it's what I'm always striving for. 99.9% of the times that I flub, it's because I'm distracted. Throw a half naked super sexy girl dancing right in front of me, and my hands start to sweat. I wish I were joking, but I'm not. Not saying it's guaranteed flubs, but it's dangerous territory. I have to reconnect my brain, and keep my focus. Lots of other things can set me off if I engage them. Broken glasses are common at weddings, as are barefooted women dancing on top of them. That one can get me too. Interesting people, something on the bar TV, other problems I might be experiencing onstage, daydreaming - lots of things can cause a disconnect. Whenever I flub, I've realized it was one of those disconnects that caused it.
As far as making mistakes, I have 3 rules for myself (that I can think of right now, anyway

) that I try to stick to:
1.
No matter how bad I thought it was, it wasn't that bad: One of the first really high end shows I played was with a band I had no business being in, about 20 years ago. These guys were out of my league at that time, but I work hard and was able to fake it well. Songs were very complicated and intense, some ballads, with lots of time changes. We were playing a spot in NYC I always dreamed of playing, and the performance was being multi-track recorded for a live CD. I was terrified. I did well despite my rattling knees, but train-wrecked one important transition. About a week later I got the tracks of the gig and immediately zeroed in on my train-wreck. I was astounded! My train-wreck was a beautifully written tasteful line I just decided to add to the song

. It was in key, and it would have been impossible for anyone who didn't know the material inside out, to even know I had made a mistake. I tossed and turned a couple of nights over that flub, but feel I learned a lot from it. After that I started checking any time I could (when gigs are recorded) and it's always the same. For me, the mistakes are rarely what I make them out to be when they're happening. Part 2 of this is I've learned to forgive myself and let them go immediately when they happen. No big deal. Focusing on a flub will only cause more flubs cuz my focus will be out the window as quickly as if that girl were dancing in front of me.
2.
Always work the flub into the tune as best as possible, and keep that Danny Partridge face happening: Gene Simmons taught me how to go WHOOOO
ooooooo
ooOM, and WHOOOO
ooooooo
ooOMs can be a bass player's best friend. They can steer you out of a brain fart, get you to the next note, and best of all - work as a foundation for pretty much anything the band could be doing. Depending on the speed, length, and articulation you can really work miracles with one of them. I also try to keep in mind something Victor Wooten drills home in his book. When flubbing, the most you can be is 1 note off from a note that will work. And I'll add that most of the other notes WILL work, even if it's a wrong one. Keeping this in mind helps me to be relaxed about whatever is going on, and getting right back to where I'm supposed to be.
3.
Never project your own or anyone else's mistakes, ever: I think this is one of the things that separates the true pros from the wanna-bees. Although I've worked with lots of pros who still don't have it down. No matter what's going on onstage, never EVER give as much as even a glance at the offender, and never give as much as a glance at anyone else when the offender is you. I can't stress how important this is. 9 out of 10 times the band themselves will think a flub on our part was intentional if we show zero signs of a flub. And what's even more important is that 9.9 % of the times the flub disappears within a second of it happening. Nobody will remember, comment, or care. As soon as we acknowledge even the slightest of flubs, it becomes a mark on the chalk board. And often times band members are counting, often unconsciously. Make 5 flubs in a set that are acknowledged and at the end of the set the whole band knows you were messing up. Keep cool about it and you're much more likely to hear, "Great set!." I'll add that most musicians are more concerned about what they themselves are doing as opposed to what you're doing.
I'll add one more thing, that ain't a rule - but motivation to work towards making as few mistakes as possible. As most know, the bass player has the least forgiving instrument. A "C" guitar chord can blend in nicely with a "G" on bass, but a "C" on bass when the chord is a G changes the whole song

. Hate to quit on that note, but it is what it is. Drummers actually have a rough time too, but they can play whatever they want and never play a bad note.