The ordinary common stuff is mostly just basic algebra, like Ohm's law, computing one of frequency, resistance, and capacitance from the other two, etc. The important skill here is not so much math but intuitively understanding the physics behind what you are doing. If you can look at a schematic and feel the voltages pushing and currents flowing and how each of the parts react to those, you can pretty much derive the equations you need to quantify things.
I also find basic physics is very useful to EEs, at least the kind of EE I do, which is designing small embedded systems. My job never just ends at the circuit or the firmware. To do the job right, which is to solve the problem not just make the circuit work, you have to have a good grasp of whatever the circuit is controlling or measuring. This requires good understanding of the system and the physics behind it.
All too often you find the people that know the system and wrote the requirements for what your controller is supposed to do don't really have a good grasp of what things are reasonably possible. They think up one means to solve the problem, then specify a circuit to do that. In other words, they know their world, but don't know yours very well. It is very valuable if you can be the one to reach accross (because they can't or won't), look at the big picture, and propose a better method of solving the overall problem. However, you can only do this if you have a good understanding of the system, which usually requires good basic physics skills on your part.
This brings up another important skill of being a good engineer, which is surprisingly rare. Always take the time to understand the bigger system your little design fits into, then look at the big picture. I find people are usually more than happy to talk about how their part of the system works, so go around and learn it. Then look at the overall picture and see if what you were asked to do still makes sense or only from the point of view of the one guy your gizmo interfaces with and that guy was only looking at his isolated problem. You may think this is a no-brainer, but then you'd be surprised how often this happens, particularly at large companies. The type of people that like to take a narrow view and work on just their little problem tend to gravitate towards large companies. There is room for people like that in a large project, having a few of them in the right place is actually useful, but it takes a skilled chief engineer to utilize these and all the people properly. That last part is very rare nowadays, and you will often find Joe Blinders in charge of stuff he shouldn't be. Even if Joe does try to look around a bit, he often doesn't know what electronics can and can't easily do. The worst is when he fancies himself a EE but doesn't really know what he's doing.
As far as more advanced math than common algebra, definitely learn to think in frequency space. I have done detailed frequency to/from time domain calculations on a few times, but the concept are valuable often. Every EE needs to be able to visualize what the frequency implications are of a time domain signal and vice versa. Here I am not talking about sitting down and solving Fourier transforms, but having a good intuitive sense of it. For me that came from doing the detailed math in college. I have done that math only rarely since, but the understanding behind it is useful every day.
