For birdie, download, extract, copy birdie to c. Ed s/startup-sequence: run it after IPrefs somewhere like this: c:run <>NIL: c:birdie .
Then download bprefs.lha (needs MUI), a GUI to configure birdie.
Visualprefs: use the installer, and then there should be a visualprefs editor in prefs that you can play with.
Birdie and Visualprefs just give you the software, but to look good its the bitmap artwork that creates the look
You can download "themes" for birdie and visualprefs just search birdie on aminet for a couple