Hey Ali.
Hope everything is well and here is my take on Keyword Research and what to focus on.
First and foremost you must execute a really great keyword research for your site and i must get this out of the way before i talk about what keywords to rank for.
Some of things i have found helpful in getting keyword research done is,
A. Competitors research. You can use your competitor sites and see what their page title tags are. Use open site explorer and look at anchor text. Just as well Semrush.com provides some really good insight on your competitors keyword research
B. your own Site search. If your store currently has a search function. Take a look at what keywords your OWN customers are using to look for products on your store. A great insight.
C. your own PPC campaign : If any, check out the existing or past PPC campaign and gage your anayltics
D. Adword Keyword Tools. : Very helpful tool and most of effective one for me.
After you compile the list, I highly urge you to go after the Long Tail Keywords 3 to 5 words long. There are your low hanging fruit. And speaking from a sales perspective, these are the words that tend to give you a higher conversion rate for sale.
Incorporate Mozscore with your keyword research . Depending on you business i usually look for Mozscore rank keywords that are between 30 to 60 and look at Global volume between ( 1500 and 50,000 ) searches per month.
Going after those two word or one word phrases that are highly competitive, does not make sense, because after all is said and done, YOU NEED SALES !
Make your keyword list and share it with us on here and i am sure we all will be more than happy to give you pointers on what keywords to go after. Remember Less competitive with good volume is the key.
Also a great way to find out the popularity of the term is also to look at the PPC price of that keyword in Google Adwords. That helps a lot as well. Sometimes those keywords that are 4 words long and have only 800 searches per month but their PPC price is like around $5.00 per click are the SWEET SPOT keywords. They convert well.
Hope this helps.
Let me know if you have any further questions.
Hampig M.
BizDetox