As a radar controller, you should always check approach plates for the airport you plan on opening, before opening, or at the very least, fly the approach.
Check if the runway headings are offset from the runway number. In most cases, the runway number will match the runway heading for the runway. For example, runway 06R will most likely have a runway heading of 060, or somewhere near there.
There are some cases though as I mentioned that the runway heading will be offset. Runway heading for the ILS LOC RWY 08L at KATL is 95 degrees, so if you clear at a heading 050 for an ILS clearance, it will be a 40 degree intercept. No good, an ILS/GPS clearance must be between 30 to 10 degrees offset from runway heading.
If you never checked the approach plate, or flew the approach, you would never know for sure what the runway heading is. The runway number means nothing when it comes clearing for an ILS/GPS approach.
1. “10.7.4” of the ATC Manual.