One thing I've noticed working in the tech field is how redundant some things can be. Whether you are trying to solve a problem or doing some maintenance, you will at some point in time be doing the same thing again. Here are two general ways that I go about avoiding the repitition:
Script it – if you need to run a command on a hundred machines, there's nothing better than spending a few minutes putting it into some kind of for loop. Depending on your environtment, /bin/sh seems to be universal for my Solaris and Linux needs. For windows, using pstools(mainly psexec) can save you a load of time especially with it's ability to take in a list of computers to run your commands on. I usually put it into a .bat file so that I can call upon it anytime later.
Document it – If you spend 20 minutes looking up a solution for a problem, it's best to spend a few more minutes documenting it so you don't have to spend another 20 minutes again when the problem comes up again. At work, we have an internal wiki that we use for things like this that my whole group can gather around and reference together. I also keep a simple text file seperated by month that I jot things down that may not fit the wiki at all. This also helps in my weekly status reports on what I've been doing. A simple grep and I can usually find the obscure knowledge that I may wrote down a year ago. We also have a ticketing program called RT from Best Practical that we document how we solve different tickets.