Rug pattern ideas

I mentioned a while ago that my roommate moved out, taking with her the living room area rug. Since then, our (admittedly pretty) hardwood floors have been pretty cold underfoot, so I've been trying to find rug ideas. Because I'm ridiculously broke (ohhhh the life of a grad student...) I'm leaning towards making one. Drop cloth + painted pattern + rug pad + rubber cement...yes?

So all that's left to do is decide on the pattern. Here I've posted a few inspiration pics...

(inspiration comes in all forms :)

Pretty kitchen, but I really like the grey-on-white pattern of the rug!

Translate this into a flat surface, obvs.

And this is the tape job someone did on their wall....picture it as the finished product

This seems like it woul be pretty easy?

Do you have any ideas? I'm probably looking for a simple geometric repeating pattern, not too busy. Suggestions are welcome :)