If you are doing engineering, then my advice would be to focus on the practical aspects of mathematics and learn more about applied mathematics than the pure variety.
This involves understanding how to program computers in a basic way (and more advanced for more complex analyses) and learning how to model real world phenomena and extract the important pieces of data out of your analyses.
You also have to be able to translate all your findings into really simple terms for the person who is using your data and they often won't know what the hell it is that you are doing in a technical sense.
The important thing for an applied mathematician (which includes to a large extent engineers and statisticians) is to put the math into context and not the other way around.
The pure mathematicians are the ones that make sure all the techniques and results are what they say they are: the applied people for the most part don't care about the intricacies: as long as the technique works and as long as you are meeting the assumptions and know what you are doing, then you can focus on what you are good at and what you are meant to do (engineering, advising, modeling etc).