Learn to read your telltales, watch the color and texture of the water, check what other boats are doing.
See the wind, feel the wind, be the wind. Nuu nuu nuu nuu nuuuuu. Muuaa muuaa muuaa muuaa muuaaaaaa.
There is an incredible amount of truth to this, about getting you "head out of the boat"
Take your weather vane off your boat, feel the wind on your cheek. Watching the other boats is cheating, learn to see the puff coming, react accordingly and quickly, when you're leading the race, the followers are learning from your reactions to the wind. You must somehow be faster to maintain the lead.