Extrude - Cut
Do you need some examples.
There is probably already an iFeature.
Let me see if I can whip up a video.
Certainly. Examples would be nice.
Here is a video that shows several different keyway styles and techniques.
Turn on your sound.
For the last keyway I should have picked a different face than the end of the part, but I didn't want to bother to redo the video for something as simple as a keyway. When all else fails, Extrude - Cut. Done!
I just realized that I forgot to demo iFeature. Frankly, it would take me longer to do that than simply create the sketch and extrude.