I’m not great at documenting the various steps of each piece with pictures, but this will give you some idea of my process for adding elements like the side support.
1. Work up a fairly specific design plan (usually in my head)
2. Create a template for the wood piece
3. Rough cut the wood and test fit
4. Do some fine cutting to adjust as needed (keep in mind sealer, glue and carpet adds to dimensional specs, so if I’m carpeting I usually trim wood to allow 1/8”-1/4” gap for these things)
5. Next I try and pre-drill fastener holes if I know where I’ll be adding stainless steel wood screws
6. Finish sanding and clean off dust
7. At least a few coats of sealer (I’m using a high quality 25 year deck sealer)
8. Glue carpet, which is usually a few steps in itself
9. Install and hope it fits!