Check the whole aperture range
The most important apertures: the wide open aperture, the next one, the “sweet spot”, which is usually f/5.6, for cheaper longer lenses (more than 300mm focal length) usually f/8-f/11, the f/11, f/16 and the smallest usually f/32 aperture.
As you use smaller apertures, more and more shutter speed is required for f/16 perhaps needed a tripod, unless you shoot in bright sunlight.
You can also learn aperture shutter speed values for different situations.
How to check it? It is good question. (I like my own question :). First choose the aperture and shoot with it for longer periods, and assume what you have learned.
For example use one aperture for a week. It is good to chose an aperture which you very rarely use otherwise. (Which you use a lot, you know already) Learn about what is it good or not good for.