Do not think price reflects quality, the best vacuum cleaner is not the most expensive one. Expensive Dyson vacuum cleaners may be trendy, but they are not without problems and there have been complaints about poor performance as well as customer service. However, cheaper models or brands such as Hoover, Kenmore, Bissell or Eureka all have similar issues. In fact, one of Consumer Reports' top rated vacuum cleaners cost just $67. There's no one model that's better than all the others and price means nothing, which is why step 2 is so important.
Read reviews on sites like Amazon.com, Best Buy, or Sears in order to find the best vacuum cleaner for your needs. If you have $26, subscribe to Consumer Reports online and read, not just Consumer Reports' vacuum cleaner reviews, but consumer feedback too which often conflicts and disagrees with Consumer Report's official recommendations. It seems everyone has a different experience or opinion so careful research is a must.
Go to stores to look at vacuum cleaners. Pull them out of the box and take a close look to verify the features are what you want.
Look at the warranty offered by the manufacturer. The longer the warranty, the better because repairs will be covered. Vacuums are faulty and prone to breaking. From step 2 you know there are dozens of reviews talking about small plastic parts falling off, cords wearing out or attachments failing after two uses.
Review the accessories that come with the vacuum model you are interested in purchasing. How long is the hose? Where are attachments stored on the vacuum and are they what you need?
Can the roller brushes be turned off? This is important if the vacuum cleaner will be used on hardwood floors because the brushes can scratch the finish.
Check to be sure the vacuum will edge carpeting. Edge cleaning bristles are important because they allow the vacuum to clean carpet all the way to the baseboard. Non-edge models will leave an inch or more of carpet by the baseboard untouched.
Investigate what vacuum accessories are available. Some vacuums come with really short hoses, but extensions can be purchased inexpensively.
Compare the cost of vacuum cleaner bags or other supplies required for vacuum use. Some models have very expensive bags and these ongoing costs should be factored into the purchasing decision. In addition, even the best bagless vacuum cleaners are not without cost. Some require the use of expensive filters so research any bagless models carefully.
Keep all receipts and packaging. There have been reports of consumers being unable to return faulty vacuums because they threw out the box. Keep everything until you are sure the vacuum meets your standards.