You need a scope to tell when they are done, otherwise you'll sell yourself short.
Get a 30-100x scope and look at the color of your trichs - that's is what matters, not red hairs or general appearance of the bud. Most people chop way too early, IMO.
Trichs are either clear, cloudy, or amber and they appear in that order, they start off clear, go to cloudy, and eventually degrade into the amber huge. You want almost all cloudy with some amber - I personally like about 25% amber trichs. If you don't see any amber, I suggest you wait until you do.
If you can't afford a scope at the moment, I suggest harvesting in at least two stages. That way you can see what you preffer. Every stran is different, and the 25% amber rule is just guidline. I would chop a branch now to hang, than chop some in a week, then chop the rest in two weeks. This will give you an idea what you preffer and in all honesty, even if you chopped now you would have some killer bud.