I work hard to be as good at what I do as I can. Recently I decided to explicitly build some new habits in order to increase my acquisition of new skills. The primary one comes down to what I'm calling sharpening.
In the past I would gain skill primarily through painful mistakes (the kind of mistakes that you never repeat), and over time I became very proficient. However, I found that this pain-driven approach was lacking for a number of reasons. First of all, it makes you look like you don't know what you're doing. If you're in a fast-paced, high-stress environment, you're probably having information thrown at you more quickly than you could reasonably absorb it. The natural reaction is to simply go home after work, relieve some stress, and not think about it again until the following day. After being in just that sort of environment and after multiple painful mistakes, I just got tired of letting the pain be the motivator for change.
Now I take a more proactive approach. Anytime I learn something new or see a piece of information I know I'll want to remember later, rather than just hoping I'll remember it I write it down. Then, every morning I review the list of things I've written down, reading each of them again, carefully. When I've reviewed a particular item enough times (when I can basically recite it from memory), then I know I can safely take it off the list. This has been especially great for me, because it gives me a practice environment where I can make mistakes or remind myself that I need to clarify my understanding on something before there are any consequences for getting it wrong. That means I make many fewer mistakes for an actual client, resulting in much happer clients, and ultimately less stress for me. The list I keep and review each day isn't very long either, maybe a dozen items. I don't review large swaths of text or go through an entire practice of something long and complex. I only write down and practice the things that I need to improve on. On a typical day, this practice takes only 10-15 minutes at the most.
In my line of work, this is especially helpful when it comes to writing code and remembering obscure and helpful syntax tricks, or the steps for something I only do once a month. It's also very helpful as I've recently changed industries from banking to medicine, and I'm awash in new terminology and people. In my new job I review not just new coding tricks, but also all the new vocabulary I'm exposed to so I can come up to speed as quickly as possible. If I still worked in IT, I would be using these tricks to more quickly learn the names of new clients, the structure of rarely-used infrastructure in a network, or anything that was important but not necessarily obvious or easy to recall due to how seldomly it comes up. In some ways, you could say that this is something we all did in school: it's basically running yourself through drills, except the test you need to pass isn't on paper, it's the test of proving whether you're competant at your job.