Bonsai Ivy?

Hello everyone,
I am new to the bonsai world but have found it quite enjoyable. One of the plants I have decided to try to make a bonsai out of is ivy. I saw pictures of ivy bonsai and thought they looked way cool but was unsure how I would develope a thick trunk like the ones in the pictures. I have taken multiple skinny trunks and kinda braided/twisted them together. I am unsuire if this is the proper way to accomplish the desired looked or should I keep just one trunk get rid of the others. Any thoughts on this would be greatly appreciated.
Thank you

The way to get a big trunk with 99.99% of bonsai is to plant it in the ground for a number of years and then dig it for bonsai. OR, buy a plant that someone else grew in the ground. Urban collecting can also work. If you live in an area with Ivy growing in yards, find someone who is clearing out and dig the plants. However, it is getting late in the season to do this.

Twisting trunks together can give the illusion of a larger trunk, especially after they begin to fuse together, but it creates problems in trimming because you must always keep track of each individual trunk and its green growth.