There's all sorts of advice out there about querying, but one thing I wonder that I don't see much talking about: when is the best time during the week to send queries?
I have an idea that it might be Tuesday or Wednesday. The way I see it, agents probably get a ton of queries over the weekend, and thus Monday morning they have a heavily laden inbox. By Thursday or Friday they've probably built up a backlog of things to do that they have to before the weekend, and thus would have to spend less time on queries. Tuesday and Wednesday gives one the best opportunity to not be lost in the shuffle.
Of course, it may just be that it's just a constant barrage of queries, and no day is any better than any other. But it's a theory.