Bits of sand dust or steel wool in the corners are a tell tell sign of preceding to fast. Use a vacuum and tack rags judiciously throughout the finishing process. It is imperative to treat the finishing process with as much care as you put into the building process. A good finish can make a medicore pieces look great and a poor finish can make a great piece look medicore. Keep your expectations high, but realistic.
Fine workmanship is aquired through practice.
If each piece you make is a little better than the last than you should feel good. These are merely observation and are not purported to be anything else. Part 2 Machines, part 3, Handtools, part 4, finishing. Are in the works, however if this is felt to be wasted bandwidth, let me know.