I've done it and yes it is more trouble than it's worth. It is the same process as any inlay work, precision cuts and fit and finding the right glue to hold them in, epoxy works best. Unless you have some good precision tools I wouldnt recomend this as a DIY project. BTW I did a lot of furniture restoration so I was familiar with inlay (and good at it) before i tried it on a guitar. Also rosewood is very open grain so it has to be trimmed very carefully to avoid splintering.