There is a lot of information on an orienteering map. You could spend ages studying the detail and admiring the cartography. But meanwhile the clock is ticking.
You may not need all the information - only what's necessary to find the next control. In other words, you need to simplify the map. Here is an example from the recent Orange course at Croydon Hill.
The leg from 4 to 5 is shown on the right - I have already done much of 12 the simplification by cropping the map down to only show this part of the course. There is only one obvious route choice - the first 500m of the leg will be along the forest road (shown as solid black line).
Then at the 3rd track crossing it's a quick right-left and then 100m to the veg boundary on which the cairn lies. So I would mentally simplify the map as shown to the right of the map extract.
Notice what I have omitted: all contours, all green shading, the three sculptures (pyramid symbols) and the other veg boundaries. I have decided these are not important to finding this particular control. They may be important on other parts of the course, but not here.
The main advantage of doing this simplification is that you can now quickly get on with the running without having to look out for all the unnecessary detail.
An advanced skill is to be able to memorise this simplified map so you do not have to look again at the map until reaching the cairn, which leads onto another tip, "Memorise".
- Skilling Up- Hints and Tips for Improvement #18, QuOnicle 159, January 2015