I'm pretty new to this whole thing and not completely savvy so I'm sure someone will correct me if I'm wrong but as far as I'm aware...each meal is MEANT to have 1/3 superfree (granted breakfast causes MUCH debate).
The point of it is you fill up on low calorie foods, giving you less room for the free foods (slightly more calorie dense) and syn free foods.
I personally wouldn't advise to have your dinner and then have fruit, simply because the chance of you still being hungry is slim and therefore you're adding extra calories than what you would normally take simply to get in your sf and therefore being counter productive?!?. I think the 1/3 superfree rule is pretty much the main one that you need to follow for sw to work and I try to follow it at every opportunity. Lunch is the only time I don't (at the moment) because I'm filling up using my HEA and HEB.
Sorry I can't be of more help and I'm sure there will be someone much more articulate and knowledgeable than me who will also post. Good luck