I always felt that late October was a good time to start budgeting for the next year. I have to admit that preparing a budget was interesting because you learned where the money went last year and got a chance to correct the trends. That's the expense side of the budget.
The income side of the budgeting process is like herding cats. Your plan and the actual outcome are unrelated. And worse - dangerous. We all plan to do better every year, which it fine. No problems with that. The danger is acting like it will happen when you budget the expenses. If you miss your income projections, but meet your expense projections, you just may have stepped closer to financial disaster.
So what do I recommend? Well, since I am out of my depth here, nothing.
But I can tell you what I do. I assume that income will be down in the coming year. Then I look at how I can squeeze any fat out of the expense side of things. If income isn't down next year, I am profitable. If income is down after all, I am as prepared as I can be.
Two articles that will give you a grasp of the big picture economics that are going on in a design firm are:
How Much Are You Worth An Hour?