Any tips for doing the front decal? Seems awkward. I read somewhere that some use some sort of plug.

Another trick that I use.

Cut away all the surrounding white border vinyl on the artwork with a Stanley blade BEFORE application.
In other words, ignore the guide line marker points that are printed on the edges of the decal art and align them manually using line of sight. (Cutting away the white border prior assists with this.)
As the name implies, those guide line marker points (crosses) seem to be little more than just a generic guide (for IJ at least) and will most likely lead to the artwork on the sides being misaligned as mentioned earlier.

Here is a pic of how I do it. I am in the process of aligning the main cabinet side (not stuck down) with the front decal (stuck down).

Note how far out of alignment with the cabinet you need to manually place the main decal to get it to align aesthetically with the front artwork. (Remember the legs hide the lower artwork).