sub wheels are good first off believe me ive been ranking #1 for a ton of keywords because of my long thought out link wheel strategy...
here is a few of the things that i do without giving away everything...
one i have the money site that has its own linkwheel using all web 2.0 props,
each of these web 2.0 props are a different "related" keyword.
i rotate between 6-8 properties for my linkwheels.
then i build sub wheels around 3-5 of the initial web 2.0 props.
i make sure the center blog links to my main money site, the web 2.0 prop and a random authority site.
that alone should get you going, oh and i use all dupe content i just rewrite it with power article rewriter and post the variations to my properties. now
get creative their are so many ways you can add, optimize and alter your linkwheels as for me i have found one that seems like it works regardless of the competition so im going to stick it out with this.
HINT---i suggest you do a google search for some ebooks regarding linkwheels---look for the old ones from like the 90's
hope this helps.