With an orbital sander and good sandpaper you can smooth wood evenly and easily with first-class results. When flush-sanding solid edge-banding, draw a squiggly line across the joint before sanding. The edge-banding will be slightly proud of the plywood veneer, so the pencil marks provide a visual aid to make sure that you’re sanding flat, and that you don’t sand through the plywood’s veneer. As you go, you can also test for a smooth, level transition by gently scraping your fingernails against the transition. If it’s smooth, your fingers will not catch on the seam between the two pieces
Let’s be clear about one thing: No workshop is perfect for everyone. If there were, I could simply give you a precise plan to follow with clear dimensions. Every person who comes to the hobby, avocation, or profession of woodworking has his own particular collection of tools and his own peculiar work style, skills, and desires for the kind of woodworking he wants to do that gives him a unique approach as to how he will lay out a shop: where the tools should go, where lumber and supplies are stored, and how much bench area he needs.