Use Print Preview!

Easy one, this! To put it succinctly, get into the habit of looking at Print Preview.

You've written a spreadsheet and next job is to pass it on to a colleague to have a look. Before you do anything else, have a quick look at Print Preview.  A lot of people will automatically print everything out that you send to them - documents, pictures, spreadsheets, you name it.  Now I'm not going to be an eco-warrior here - the rights and wrongs of this are not the point.  The point is that in the real world and that's what (some) people do.

Now I don't know about you but I'm certain that my boss wouldn't be very happy if I handed him a spreadsheet and he ended up sending 100 pages to the printer, 90 of which were junk.  It really is that simple.  A quick look a Print Preview can save you a lot of (easily avoided) headaches!

On top of that Excel provides something called "Page Break Preview", which appears on the "View" tab in Excel 2007.  This gives you a visual guide to where all the page breaks will appear when you print it.  The dashed lines are where Excel has put a page break for you, the solid ones are added by hand.  You can drag these around as needed.  When you've finished switch back to "Normal" view and you're done.  A small investment of time goes a long way!