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
Instead of using a container to mix a small amount of epoxy, just make a mixing surface on your workbench using painters tape. Simply lay down strips, overlapping the edges so the epoxy doesn’t get on your bench. When you’re done, peel off the tape and throw it away. This mixing surface will work for more than just epoxy, you can use it for wood glue or any other material you need easy access to while working on a project.