I'm also having a problem making it look perfectly round on top with nice edges and not like wavy..
If any one can help I would be very greatful.
I know a lot of people hate the Wilton cake saw...but I actually love it and have no problems. I also always cut a cold cake..maybe that helps.
Hi Rob, I had a huge collection of cake saws/wires/torting devices until I came across my lifesaver tool: its the Kitbox brand cake marking tool and I've never looked back since. (I've written a review here with pic: http://cakegeek.co.uk/index.php/reviews/). I use that in conjunction with a long bread knife and cut cakes when they are cold (but not refrigerated.)
As for the wavy edges, a small spirit level is your best bet here (along with having torted your cake level in the first place. Each time you add a layer of buttercream followed by cake, check that the top is level.
Hope this helps!