It’s up to you what areas of your homemaking you want to plan. Try different things and see what works!

Planning is a prelude to having productive routines. While routines are the gospel, planning is what helps formulate those routines.
Planning is ever evolving. As situations and seasons change, we find our systems lagging, lacking or just not working!
Think about your system, what still works and what doesn’t. Think about incorporating new ideas you have gotten and reformulate your plan.
Sometimes, though not necessarily, you might also need to change your routine to incorporate the new plan. As much as possible, try not to change everything at once. Doing it gradually, one plan at a time, will make it easier to stay in control of your home.
Revisit old systems. Sometimes, after a rough season or changes in a situation, reverting to old plans and systems can bring back a sense of calm to your home and family.