"I don't wear clothes"
Translation:Δεν φοράω ρούχα
As mizinamo said, ρούχα is plural.
The article 'τα' is ommited, because in this case, "I don't wear clothes" declares that a person is not wearing clothes in general, at all. Imagine that this phrase might have been "I don't wear clothes while taking a shower." (The speaker is generally speaking.)
You could only use a definite article to indicate a crtain kind of clothes that you don't wear, but that would normally be accompanied by a pronoun.
for exp. Εγώ δεν φοράω αυτά τα ρούχα - I don't wear/I'm not wearing these clothes.
There are also a few cases with no article, only a pronoun. (the pronoun τέτοιος-α-ο might actually be the only case.)
for exp. Εγώ δεν φοράω τέτοια ρούχα - I don't wear such clothes.
I hope I helped a bit. ^.^