I started my career in accounting and eventually ended up in IT then in management consulting. A big part of my success is attributed to my Excel skills. Being able to handle a large amount of information and translating it to useable data for decision making and action is the skill that you should be aiming for.
Here are some tips:
1. Speed - You should memorize the shortcut keys for common tasks you do in your role. You should never be using the mouse to do simple things like activating pivot tables, auto sizing columns, adding/deleting (rows, columns, sheets), selecting ranges, flying to the end of the range etc.... To develop your skill with short cut keys, stop using a mouse for one week, or even one month. You will be forced to learn all short cut keys, without a mouse. It's actually possible to use ms excel without a mouse. After this excercise, you will look like a guru when people see you use ms excel. It should look like you are playing the piano when analyzing your next spreadsheet!
2. Pivot Tables - MS Excel's most powerful feature is pivot tables. Analyzing data that comes from a database in order to illustrate it in visuals or to group by using meaningful headings to provide insight is what makes it so powerful. Google "pivot tables" to learn more.
3. VLOOKUP formula - This is my most favorite formula and has saved me soo much work from manually doing comparisons. Again google this and learn it.
Good luck in your Excel career !
I use Excel all the time for financial spreadsheets and data mining, but everything is customized for me since I'm computer illiterate.
Marcus Aurelius: Tell me again, Maximus, why are we here?
Maximus: For the glory of the Empire, sire.
Baked, not fried... the healthy choice.