Do you have a great product or service that you can create a market for?

The first and the most obvious step would be to find a domain name that will be a traffic magnet. There are many reasons to choose certain domain names while avoiding others, so let's get an idea of what to look for.

MISSPELLINGS;
Due to the recent overbuying of domain names one of the tactics that hosting companies are using is to promote misspelled domain names.  While it makes sense that a hosting company has neither the time nor inclination to dig up  good domain names for their clients, it can kill a new business in a heartbeat.  It's simply a matter of getting accounts in and set up as quickly as possible, disregarding the negative consequences to the clients chance for success.  The odds that a misspelled, one key off, or bad grammar domain will work are zero to rarely.

Examples of the use of Misspellings =Jewelry/Jewellery: Jewlry, Jewelery ~ One Key Off = Google: Googlw or Googlr (R and W side the E on your keyboard) ~ Bad Grammar Plays = Sales/Sells: Salez/Sellz

REVERSED GRAMMAR;
Having keywords in the domain name will always pull better, from the search engines perspective at least.  However, it won't ensure the domains pulling power from the human perspective.  An example of this would be Salesauto.com.  While the keywords are there, it simply isn't conducive to a proper search term and therefore inherits poor grammatical pull.  It simply isn't natural for a human to think in reverse.  Trying to be as natural as possible in the way a human thinks when doing a search might be as important as how a search engine reads the domain.  Keep this in mind when crafting your new domain name.

PLURAL vs SINGULAR;
The whole point of targeting a market is to also target the "searched" keyword phrases that will be used to find you.  The key here is "SEARCHED", the terms must be searched for consistently. Subtle changes in terms can have huge effect on a keyword or phrases organic pulling power. 
Let's look at a couple of examples:

MP3PLAYERS  Returns 56,000,000 results and is searched 22,000 times per month
MP3PLAYER  Returns 128,000,000 results and is searched 165,000 time per month

The singular instance of this term has nearly 8 times the organic search value.

Here's something interesting, if the term is changed to MP3 PLAYER it sends the "monthly searches" to over 20,400,000! This leads me to believe that mp3-player.com could probably be developed to grab a large market share of these searches.

To find organic search values, simply do a Google Search for the EXACT phrase you are targeting and you'll see how many instances are returned.  Remember not to use spaces between words unless you'll be using a dash in your domain name.  Next,  set up a free Adwords account, go into your manager and then use the keyword tool to see how many monthly/yearly average searches your terms actually pull.

DASHES;
One of the biggest mistakes is to underestimate the power of the keywords within your URL.  While dashes make a domainer run for cover, I like to use them as brand protection.  Considering that you can own strong keyword rich domains by simply placing a dash within the name merits consideration. Of course it depends on the keyword terms you want to target.  I do not recommend investing in a name with more than one dash (-) and only if it separates two very strong keywords. Examples of this would be; Car-Sales.com or Free-Software.com, download-music.com..Etc  Names like these (dash included), can pull massive amounts of organic traffic on their own. Keep in mind that Google strips the dash from a URL.  This means that it will see the keywords as being grammatical in nature. Auto-sale.com would pull and rank strong for the search  "Auto Sales".  This effect can actually pull harder than if you had no no dash in the URL, in some cases.

Primary keywords are by nature the best pulling terms possible.  The reason a single syllable primary keyword is so expensive is due to the awe-inspiring organic pulling power it has.  This gives us a clue to why Bank of America paid over $1m for LOAN.com and why FUND.com recently sold for over $8m.

The final conclusion is to find a a name that is keyword rich yet short and sweet.
Since Google serves nearly 70% of the search market, you'll want to go straight to the source when doing your research for domain name prospects.  Create an adwords account and use the keyword tool to discover terms that are related to your industry or niche and that are also searched.  Avoid having to brand your name, by having to market and promote an unrelated domain name you'll be starting out with a disadvantage..  By seeking a keyword based name, that has a history of being searched, you'll inherit a portion of those results.