Progressively less and less.
When I was a catechumen, and when I was just received into the Church, I read all the prayers from my prayerbook every morning and every evening. But then, at some point, I noticed that that was just a mechanical thing; I was not really moved by these historical prayers of St. Basil of St. Makarios or St. Ephraim etc. Well, sometimes I was, but not on a daily basis. On the other hand, I just never, ever was able to pay spontaneously, in my own words. I do not even know why - maybe it's my anti-theist, Theomachian upbringing in the former USSR. So, I began to shorten my time in front of the icons in my icon corner, and shorten it, and shorten it, and shorten it.
For a while, I was able to at least mumble the Trisagion. Now, I am back to square one - I just cannot pray. Every morning and evening, I come to my icon corner and silently cross myself. At best, I say, "Lord, have mercy." It only takes a few seconds, that all for me now.
Yet, if I see a prayer request on this forum or on Facebook, I always cross myself and ask God to have mercy on the person for whom the prayers were requested.