I too like your photos and think I have similar issues to yours - I have a good camera but often my pics don't have the detail I hope for. From my reading around the subject, it seems that the critical points for macro photography are (i) eliminating shake (which is exaggerated in macro mode, so even pressing the shutter can blur the photo) and (ii) getting the depth of field right. For (i) the easiest way to fix the problem is to use a tripod and if you have it a remote shutter release cable; for (ii) depending on your camera, you may be able to see the depth of field with a preview (often by pressing the shutter release half way).
I'm no expert, but a keen amateur - hope these suggestions help!