In one embodiment, a system comprises a first baseboard element, a second baseboard element, and a spline configured to couple with the first baseboard element and the second baseboard element. In another embodiment, a system comprises a first crown element, a second crown element, and a spline configured to couple with the first crown element and the second crown element. In another embodiment, a system comprises a crown spline, a baseboard spline, and a wall element configured to be coupled with the crown spline and the baseboard spline. Other embodiments are disclosed herein.