It is good to read that you spend a lot of time on looking for ideas and lesson planning as this certainly would help to make your lessons creative and interesting.
I am not sure if I could give you some real advice on how to do this with limited time spent on it.

Visuals and other materials you may use in class normally are a result of lesson planning, and to me, that would mean that you would need to spend an appropriate amount if time on both as one follows from the other.

For private lessons with a single student, you should perhaps use visuals and similar materials made available by a publisher; perhaps you can get them for a public or a school library.

With an adult person as a single student, you should primarily train speaking and listening comprehension. Then, write down important key words and their related structural items on a blackboard or similar. So, the person will have both sound (spoken language) and its written counterpart in both visual and audio forms. If the contents of your lesson are adapted to that person's individual needs in daily life, it will be easier for that person to commit that to long-term memory if various physial sense are addressed simultaneously.

Hope this helps a bit.

Good luck!