One of the aspects I find valuable with Kanban, is the work visualization. However, sometimes I find that the work is so chaotic/iterative and collaborative in some portions of the process that the standard columns and rows in the kanban board don't provide enough flexibility. You'll see this when you have one work item that requires separate but related work from multiple team members due to their specialization.
In these situations, I avoid trying to fit the highly iterative work into columns and rows, and collapse them together into a single step on the board. The problem I run into when I do that, is it becomes hard for the team to figure out who is working on what and what work remains to be done on the work item.
To solve this problem, I apply colour to the work using coloured stickies that I "tag" on work items to denote what's be done on each particular work item.
In this example, the team pulls a work item (user story) into the "Create FitNesse Template and Automate" column of the board. To move an item through this part of the delivery process, requires the team to define detailed acceptance criteria in the language of the domain model, get it into a FitNesse page, and then automate the tests. This requires at least three specialized skillsets, a business analyst who understands the requirements that can help define the acceptance criteria, a developer that can verify that the acceptance criteria can be automated and develop the automation code if needed (fixtures etc.) and an architect/product owner that can review the acceptance criteria. Also, the work is not necessarily sequential and may be done in parallel or require multiple iterations.
To help visualize the work for the team, we applied coloured stickies that are tagged to each work item once something has been completed on it. For example, if the FitNesse template is done and data is defined than we tag it with a red sticky. If automation is completed / not required than it is tagged with a blue sticky and upon review from the architect/product owner we tag it as yellow.
A neat result of this process, is that each team member can immediately tell what item they should be working on. The business analyst just needs to look for work items that are missing red tags, which is a signal for them work. Similarly, blue for developers and yellow for the architects/product owners.