We're doing some redecorating and I've learned about trim. Trim is placed over the ugliness that happens when two surfaces meet. Like a floor meets a wall, or where a window/door meets a wall. Code has lots of trim.
I forgot shims. Shims are inserts of various thicknesses that make things fit. Since buildings are rarely perfectly square, they also shift around over time, and even standard sizes are often not all that standard, shims are needed to raise the height of something or make for a tight fit. Code has lots of shims. - Todd Hoff