There was a time during the mid-century where styles went minimalistic. Structures were designed to be as simple and functional as possible. This allowed for cheaper construction costs as most embellishments were eliminated. However, functional exteriors and interiors can be boring, the pendulum swings and there has been a steady return to more elaborate designs. This is evident in kitchen’s which now incorporate ever more complicated cabinet additions, like elaborate crown moldings.

This complicates things for the DIYer, as the installation of such pieces can be difficult and involve a little geometry as well as a dose of thinking outside of the box. Below are some photos to illustrate what I’m talking about. My best advice to a DIY’er is to have the proper tools, take your time, and practice on some scrap wood before you destroy more expensive flat crown and crown molding.

This is a top-of-the-line compound miter saw. It adjusts easily and consistently. In addition, it makes very precise cuts.
A regular miter saw can make a straight cut as well as an angled cut. A compound miter saw can do this, plus it can make the angled cut in two separate planes. This is necessary for complicated trim work. The downside of this type of saw is that it is usually bigger and always more expensive. For simple trim work a regular miter saw would do the job.
Above is a very complex job. #1 is a light rail for under-the-cabinet lighting. #2 and #3 are the two pieces of the cabinets crown molding. Every piece requires multiple cuts.
Here you can see the two piece crown molding from two angles. Note that you are already dealing with multiple angles even before you start cutting.
Here is just one wall. Each cabinet has multiple pieces of molding, but everything has to look connected.
I like using “Instant Bond” to stick the various pieces together. Naturally, I’ll also nail them and provide additional bracing as indicated.
It is also necessary to use hand tools to make fine adjustments.
Here I’m using a coping saw to make even finer adjustments.
I’m using some scrap wood to align the door with the flat crown.
Here you see a major problem in a minor space. The trim is leaving a gap giving it an unprofessional and unsightly look. The solution is complicated as it involved cutting a filler piece at two different angles (a compound cut).
Here you see the complex solution that involved multiple cuts and adjustments.
Here I’m mounting this piece. You can see that the gap is now missing and the end result looks great.

As you can see, it can be pretty difficult to add embellishments, and the average DIYer may do better with a simple cabinet install. If you want a more complex job it could be a time to contract an expert crow as it will save you a lot of time and grief in the end.