The strategy I have the most success with using my light(490w) is the good ol SCROG. It makes spreading out your canopy easy without any tiedowns to get in the way. As long as you don't veg for too long it also does a great job of keeping most of your buds in the sweet spot of your light.
Don't be scared of topping/pruning/etc, especially in veg. It will always grow back as long as you leave something behind. In my current Problem Child diary I took a small plant that was only a few weeks old and took everything but the first nodes on the bottom branches for clone cuts. That donor plant is almost a meter tall now and bushy as hell after a couple cut backs.