How to build packages from tarballs without makefiles

[David Liontooth <liontooth@cogweb.net>]

I occasionally run into tarballs without a makefile. How do I turn those 
into Debian packages?

Here's an example -- otk_lib from http://otk.sourceforge.net/.

# tar zxvf otk_lib_0.47.tgz
otk_lib/gadget_lib.c
otk_lib/letter2vector2.c
otk_lib/otk_lib.c
otk_lib/Readme.txt
otk_lib/gadget_lib.h
otk_lib/otk_lib.h

I rename the directory libotk-0.47, enter it, and run dh_make -s, 
getting "Currently there is no top level Makefile." The Readme.txt says

/* To Compile:   Directive in code should detect environment and do the 
right thing.    */
/*  
Unix/Linux:                                                                         
*/
/*        cc -O -c -I/usr/X11R6/include otk_lib.c -o 
otk.o                              */
/*    Link with:    -lGLU -lGL -lXmu -lXext 
-lX11                                       */

Do I put these into debian/rules? Where?

I was hoping I could make a few changes and run fakeroot dpkg-buildpackage.

Dave