sign into your google acct. then go here:
whatever your hub is about, try out some words to see how many searches are being done when people look for your topic online. Take the ones with the highest number of searches, and incorporate those words into your text capsule and photo capsule headings. (use in your other capsules too)
You will be able to tell by the number of searches which ones are best used in your hub title too.
For example: my hub on WTC Ground Zero illnesses I just tweaked it today because the views were not so great. After tweaking, it has rec'd over 40 views in less than 7 hours. That is more than it got in 8 days it's been published!
Go to the link, type in 100.00 for your budget - don't worry it won't charge you anything, it is just to be able to have access to keyword function.
I put in WTC, and got 135,000 searches, hold mouse over the dead space after the 135,000 and it will say "more like this". do that for any searches that have high results and it will give you more choices.
I took the choices and used them in my capsules and in my text.
Another example is Princess Diana, everyone does searches for her still after all this time, By adding the word Biography because it was a good keyword that came up high (297,000) I put it in my title and my views went up 65% in the last 10 days.
So I hope that helps you figure out how to use your keywords.