When I bought my first house... Oh boy did I have lots of mismatched furniture LOL.

Depending on what your furniture is made of there is of course using the " distressed" look . Or there is always good old paint.

My daughters first apartment was a tossed together mess lol ... She really played it. She loves all the different looks and finishes. I think it looks wonderful.

As for organizing ? My golden rule is once everything is cleaned and organize .. anything you bring in needs a home. Mail can be gone through as soon as you get it and toss out junk stuff the garbage. My shoes and purse are put right away , My purse is always hanging on the inside my closet .

Good luck