Petey, I use epoxy for my brass and copper powder inlays. I add enough of the powder that the epoxy/brass mixture turns into a putty that you can just press into the recesses (wear gloves). You really have to use a lot of the powder or it will just turn it a snot green color so experiment first to get an idea how much powder it takes. I've never measured but it is probably at least 50/50, maybe even higher brass/epoxy ratio. I use a 30 minute epoxy to give me enough time to mix and get it into place. After leveling and sanding, it helps to use a smooth piece of metal to burnish the inlay to get a better shine before applying a finish. One nice thing about this approach is that it is easier to use on the sides or rims of bowls for example because the putty stays in place regardless of orientation.
--Nathan, TX. Hire the lazy man. He may not do as much work but that's because he will find a better way.