There are some simple techniques that you can incorporate to effectively make use of your keywords. The most important step is to choose the right keyword (if not the best). I have really suffered because of my decisions with wrong keywords. So, its really important to choose the correct keywords. The other thing is to correctly make use of them. The same onpage principles apply to Hubpages that are applied on any other website. You need to put your keywords which are the most prominent to the spiders. So, put them in your title and in the titles of your capsules. Also, don't forget to give your images alt and title tags and fill your keywords there as well. Also maintain a nice 2% density in your content but put them more frequently in your opening and closing paragraphs (or capsules). I know these are basics but they are the most important.
Hope this works. :)