In Las Vegas, you should be able to have your windows open quite a bit. Not an option here in Chicago unfortunately. Fresh air will be your biggest ally in mitigating a smell. As stated below, have your ducts cleaned out also. Some owners have never done this, and god only knows how much dander, dust, and other stuff has built up over the years. The air circulating through the systems of the home is basically spreading that stuff back around your home constantly.
Re-painting will help quite a bit also. I would prime all the walls with a product like "Kilz" interior paint, which will essentially seal all stains and odor into the drywall - before painting. As Mary stated wisely - paint the ceilings. Yes it's a pain - but it will do wonders for how it looks and the effectiveness of removing odors.
Steam cleaning the carpeting will also help freshen up the home and remove odors.
If there are pet odors - the carpeting and/or hardwood may need to be replaced, especially if the cause of the odor is urine. If it's gotten underneath the flooring, then a simple cleaning isn't going to do the trick.
Candles/air fresheners definitely "help", but in my opinion - they only "mask" the odor, instead of addressing the root cause.
Hope this helps! Good luck!
ALso on a budget placing small containers of vinegar discreetly around the house will absorb odors. These have to be refilled every few days as they evaporate.
A good cleaning works wonders. Open all doors and windows while cleaning.
If the budget allows obviously replacing the carpet and drapes would work wonders.
Replacing A/C filters at the low end of the budget and at the higher end having the ducts cleaned can help.
The best remedy I have found for getting rid of odors in a house is a coat of primer on the walls and ceiling. The ceiling is the key. Most people do not repaint the ceilings. Over the years, as heat rises the odors get trapped in the pores of the drywall on the ceiling. If the ceiling is stained from cigarette smoke that is the only way to remove unpleasant/ stale smells. The primer will trap the smells. A fresh coat of ceiling paint will also brighten up the place and give it new life.
2. Have an A/C company clean all the A/C ducts.
3. Clean interior i.e. if non-carpet use liquids to mop.
4. Carpets professionally vacuum, rent equipment to shampoo or use Fabreze products to temporatily irradicate order.
5. Get a time and plug a good i.e. Eucalptus air freshner. (the timer will save you money i.e. set timer to activate 10:00 am and shut down at 6:00pm).
6. If a tragedy occurred consider hiring a professional before steps 1 thru 5.
Take care and good luck!
BB BG BH!
The only exception would be a home with a long time smoker.Something like that will need to have all the interior walls and ceilings scrubbed,carpets replaced and the entire place repainted.