A great tool for creating figures is Adobe Illustrator, which I have used successfully for over 24 years here at UCD working with researchers and scientists to create their images into high quality publication ready images . This method also allows transfer to posters, PowerPoint presentations and other materials. I have attached an example of work done for DR. Ivan Schwab for his research on the Jumping Spider Eye.
For 2D scientific illustrations, PowerPoint, Inkscape, and Adobe Illustrators are the top software choices. Inkscape is a free open source software, and PowerPoint is usual free along with your operating systems. You can check out my review of these software here [ https://youtu.be/jR6tM0H_qno ] and the tutorials for making scientific illustrations with these software applications.