Because you’re using the Wonder Wheel to analyze keyword relationships for site structuring, the obvious place to start is with your site keyword – or the topic for your site.

From there, the “branches” off the keyword may be logical category ideas – the branches off them may be logical subcategories – and so-on.

(Obviously, by then analyzing the traffic, value and competition around the keywords in Market Samurai – and focusing on high traffic, low competition, high value keywords – you’ll be able to focus your site structure onto the most profitable keywords.)