Starting with Kanban, I'm not sure about how granular my work items should be. While you find lots of concrete recommendations about how to choose the WIP, most of the Kanban tutorials I've read stay quite vague about the size of a work item (= a card on the board). For planning and estimation, people often recommend to keep the size of an  item small, say 2-16 hours. Does the same apply for Kanban? Is there always a 1:1 mapping from my plan to the board?If there's no best practice or general recommendation, which factors would influence my choice of work item granularity?
Kanban: How to choose work item size
kanban
I'd say make items the size they can be easily made to. Start with what you do now is one principle of Kanban. So split the work like you do now. Agree to pursue incremental, evolutionary change is another principle. Start implementing small changes if you see problems in the way you split work.Don't get hung up on analysing and designing your Kanban process beforehand. Start doing and continue doing things that work and try to fix things that don't work.