I book as soon as I know where I am going. I usually know my fun travel dates a year out. So, I plan a trip and book hotels.
Sometimes I adjust where I am staying (I changed my European travel itinerary 3 times last summer and cancelled the hotels).
But I check. 75% of the time, the rate has increased or not changed as we get closer to the travel date.
25% it has dropped.
Since they are not pre-paid, I am usually better off booking as early as I know.