I usually bulk until my abs start blurring out, and check body fat gain week by week with pictures. Once you've reached the point where you lose your abs, start a slow cut back down by removing some, not all, carbohydrates.
As far as your question for carb timing, check out carb back loading. Alot of bodybuilders are starting to use it and I use it myself. I feel alot less lethargic during the day, my appetite stays high, and insulin sensitivity is high without the unnecessary carbs. Definitely keeps unnecessary body fat gain in check.