Build/Create makefile...
That functions is slowly improved over time, so recently the makefiles produced are sometimes usable (when compared to 602 version of Create makefile, which require further edit every time).
Also try to search forums for "umk" posts, there can be some information too.
I think that while still not perfect, new "Project/Export project" works very well. At least, it does not require many Makefile edits and produced Makefile is using relative paths...