A quick web search gives many answers.
Sensing's motto is 'seeing is believing' (also called Observant personality).
Importance is placed in things that are real and tangible, and the here and now.
Contrasted with Intuitive (which does not start with the letter N), as a personality that is often thinking ahead, taking leaps of imagination, and less able to focus on practical matters.
Creating a character who is more Sensing than Intuitive probably means someone who looks for doable, practical solutions. They probably hit a limit of 'talk' before it soon turns to action. They have a fanciful imagination, but it's not the decision-making voice in their head. They are not the type to allow all the possibilities to overwhelm them, instead they may be busy 'fixing' before they are quite sure what the problem is.
As a frame challenge, Meyers Briggs has been criticized by writers as a poor tool to create characters (although it's popular to try) because it doesn't inform how a character changes through their arc, or what they need to discover about themselves. It's not 'wrong' but it just isn't helpful for stories.
The structure of most stories is to take a character out of their normal and put them under stresses until they change. Over the course of a novel, the main character would appear to flip polarities in a personality test, passive then active as the action turns direct, dreaming of a far-fetched desire in the 1st Act and making practical decisions by the climax.