Adding a field sampling grid, placed at a desired angle, to a map

I am a teacher trying to assist one of my students with a question. We are using ArcGIS 10.1 and my student would like to add a sampling grid to a map, i.e. a grid that he can follow in the field when collecting samples. It would not be a true N-S, E-W graticule, but he would like to be able to adjust the angle, for example, to tilt the grid at an angle of 45 degrees one way or another. I have looked at "Help" but do not see an obvious solution to this, in that most discussions there refer to setting up grids relative to a given projection, etc.; we "think" that we looking to do something that is simpler than that.
Thanks for any advice that you can offer to a couple of non-experts.
Brian