Just read and try to understand. Stop focusing on time if you have the habit of looking at the watch. Maybe even try not using a watch (still set a timer). Arbitrary tips like "10 in 10" and "15 in 15" is just pure bullshit.
I sit up straight on the edge of my bed and set my phone timer for 10 minutes. I like to imagine facing difficulties on a test and see myself responding to them well.