Did you realise you fly at a different altitude depending on if you are going east or west?
The first 3,000' above ground level (AGL) you can fly at any altitude and any course. Above 3,000' AGL flying at the correct altitude is dependent upon whether you are going East or West..
Between 3,000' AGL and 18,000' you should fly as follows:
If you are flying using VFR (Visual Flight Rules):
If you are flying EAST , Course Heading anywhere between 0 degrees and 179 degrees (Basically the EASTERN HALF OF THE COMPASS), you must be at an ODD THOUSAND + 500 ft. (ex. 7,500')
If you are flying WEST, Course Heading anywhere between 180 degrees and 359 degrees (Basically the WESTERN HALF OF THE COMPASS), you must be at an EVEN THOUSAND + 500 ft. (ex. 4,500')
If you are flying IFR (Instrument Flight Rules).
If you are flying EAST you must use and ODD THOUSAND ft. (ex. 5,000')
If you are flying WEST, you must be at an EVEN THOUSAND ft. (ex. 8,000')
Above 18,000 ft. you fly always fly at FLs (Flight Levels) of ODD or EVEN Thousands of Feet (depending on your direction).
Thanks Richard for the fact!!