I do a rebalance pre-emptively when I expect to go out of balance. I don't wait for the big new year distributions, but beforehand I usually do some trades for tax issues and adjust the balance in those trades I am doing anyway. No extra commissions.
Kind of exciting to put yourself out of balance, then often ride sort of a santa claus or january reinvestment rally. You don't have to put yourself at the mercy of buying at higher prices with the reinvestment crowd, but magically fall into balance with the distributions.
I don't believe in the conventional wisdom of auto reinvestment in same securities because it tends to push you further out of balance, among other drawbacks.
A smilar thing can be done with most any trades you make at any time - just tweak the number of shares bought or sold to aim yourself more toward an ideal balance.