What shall you do to increase evaporation rate of water?

You add more heat to it (water can go no hotter than 100 degrees no matter how hard you heat it).

that isn't true. if you use a pressure cooker you can heat water hotter because you have raised the pressure the temp can therefor be raised.

Yes, the critical temperature of water(the max temperature that water can exist as a liquid, even with unlimited pressure exerted) is around 373.95degrees Celsius. To answer your question, you can add heat, decrease vapour pressure, or increase surface area.