Hi. New to this forum. Figure I should enter trying to help somebody else out. I know the favor will be returned many times on this forum.
I guess I'll try to give you advice since nobody else wants to. I don't get why the others believe you should get so much flak just for not having a camera to take a picture with...
Okay. So.
You've got the one main trunk, yes, and some branches coming off of it. I'm relatively new to bonsai too and starting a cascade as well. So I'll tell you everything I've observed and practiced so far. You've got a tree that is literally just "growing down" like a vine falling off an edge. Your tree has no canopy Do you understand what I mean?
Even on cascades you will see a triangular canopy even though the leader is moving down instead of up. This makes sense because that is the best, and really only, way for a tree to ensure it gets light to all branches and foliage from top to bottom. If there was a greater horizontal of foliage on top of the tree than on the lower layers of the tree, the lower portion would be shaded out and eventually die.
Even though your tree's canopy will be sparse right now you still need some place to start and you need to ensure that with time you will have a believable canopy.
I'm not familiar with the plant that you're using but I hope it will back bud so that the spots closer to the trunk will send out branches for you to get that canopy from. It is essential to the believability of the final tree.
I imagine that you can use wiring to some degree to get branches where they need to be to start building that canopy.
In all bonsai, and this cascade included, you must make every choice in what you are doing with the future in mind. You need to leave what is necessary later on, as well as things that may be necessary in case your first plan doesn't work. You can't always just choose how a tree is grown. Sometimes the plant rejects the plan and kills your most vital branch. You need to always have a plan B and plan C and maybe plan D.
A tree is not grown in one day. Or one season. No matter how you prune or wire the plant. It all takes patience and imagination as well as an understanding of what really creates the image of the bonsai. If you need more of an idea what I mean about the canopy, simply look on google and notice that all the trees have green growth from top to bottom in the form of a pyramid. Make sure your tree will be able to send out branches to help create that.
The way you can learn how to make a bonsai is, most importantly, to look at bonsai. And look at trees in nature. Observe the trees and ask yourself why they are the way they are. The most wonderful thing about nature is that everything happens for a reason. Because they have to happen that way and couldn't happen any other way. Nature has rules. It makes the game easier.
And most importantly, develop patience and enjoy nature everywhere it presents wonders.