First post, I have been remodeling our walkout basement, looking for an inexpensive program to design a bathroom for the basement. Plan on using an upflush toilet package with a shower and sink added. This bathroom probably won't be used much. Size maybe 9x6 ft. -I have other questions but will post later.
In the reference section, look for a big book called "Timesaver Standards for Architects" or something similar. You'll find basic bath layouts for a variety of room sizes, along with minimum clearances and handy tips. If you find something you like, then just copy it and you're done.