What is the most important thing to remember when using color pencil medium? I'll give you a if you do good.

I think its to outline darker and shade in lighter but it depends on what you're coloring or drawing tbh, but also don't press super hard

I don't use coloring pencils much, but I do know that medium pencils are meant for tracing or even outlining if you press hard enough. A proper shading pencil would be a 4 HB pencil because of it's boldness and blending using that pencil would make a bold shade.

Medium pencils however would be lighter and would be best when shading in daylight. Some coloring pencils seems to be a bit more dual, so try getting a professional brand to have the best result. If not, try coloring and blending harder to get that nice shade or outline from a coloring pencil.

Hope it helps and have a wonderful rest of your day/night!