Fundamental - There is lot of stuff going on right now with BREXIT because of which it is not easy to interpret GBP's strength or weakness. But having said that I m sure that BREXIT will not only impact GBP but also EUR, so we can assume that the BREXIT effect will mitigate itself if GBP is traded against EUR. Also there is some expectation for GBP to increase rate within first half year & since we are already in 4th month of the year, I m expecting the rate increase within next two month or so.
Summary - Wait for price to reach 0.8100-200 zone (if it reaches there) & try to find short setup according to your trading strategy & execute it will extreme confidence. Plan your trade & Trade your plan. Good Luck !