Hi, I took both at GCSE so hope I can help! It depends on your strengths; geography involves a lot of graphs and interpreting data, memorising case studies for different topics, understanding and describing physical processes etc, so you need an interest and understanding of the world around you. In history, you obviously need strong essay skills as the majority of the exam is essay based, depending on the exam board you'd also need to do some source analysis. You'd need to memorise specific years and a few statistics since the questions are usually focusing on a specified time period. Which other subjects are you thinking of choosing, and which subjects do you enjoy? I personally chose to continue history to A Level and I love it, but I do miss geography.