Deodorize my apartment?

I have a small apartment that I think is probably pretty old, but they refurnished it before I moved in. (new carpet and paint, about 5 months ago). My apartment has a musty smell mixed with paint. It seems to smell more when it's humid outside. I hate the smell and have tried air fresheners but it doesn't get rid of the smell, it just slightly covers it. Ive read some things about using onions or vinegar to deodorize rooms. Has anyone used these and how? Or are there any other ways for deodorizing rooms that anyone has found successful.