If I were going to wire some real movement into the tree I would first wrap with raffia or similar product to protect the bark and support the fibers allowing for more flex w/o cracking. Then starting the wire anchored in the soil as mentioned above, start coiling right at the base, the wire will need to be pretty stiff to hold the bends and curves, from the pics I would guess copper as thick as a pencil, maybe a tad smaller would do it. I would aim to put some bend into the tree w/o leaving more than 1 inch of straight area in the trunk and branch lines. the 1 inch thing is rarely possible but makes a good goal to just keep in the back of the mind when wiring. Also the lower you can start your first main bend the more convincing the cascade will be, I would want the first hard bend there where the sub trunk starts, nice and low.
Another way I picked up from Grampz is to wrap(he likes coach tape and vet wrap better than raffia), then run 2 copper support wires the long ways of the line on the the underside. Then wrap again before adding your normal coiled bonsai wiring. If dealing with a tuff subject you can also employ guy wires.
Here at home I have braided copper wires to make a support bar that is tied into 2 places on the tree to help hold a curve, most will use rebar for this. Cut that red stuff off of there and get your supplies (raffia and wire)and if need be I can scrounge up some pics and help with the details if you need it. I can see some bending and a slight change in angle at next repot will really help this one out if cascade is want you want.
Here is a popular online article on beginner wire technique to share with you.
http://www.gsbf-bonsai.org/daiichibonsaikai/wiring.html