There are many ways to tackle AR subset. My top tips would be to use Medify, Medic Portal, and the ISC Medical book for practise and I will also guide you through examples to explain in greater depth each question you are confused with. Medify and Medic portal have a bank of questions which provides you with lots of practise with this section. AR is all about practise and you need to make sure you can find patterns really quick. after all, we know how time constricting the UKCAT is, but finding the pattern can make you answer many questions in the "Set A or B or neither questions" which you find majority of the time.the biggest life saver would be the SCANS method if I had to only give you one advice, which stands for Shapes, Colour, Angle/Arrangement, Number, symmetry. UKCAT tends to follow these rules for their questions, and the more you practise using SCANS the more likely you will get a higher score in the UKCAT. also another thing is, when you make a mistake, you need to right down the pattern you got wrong, and remember the pattern for next time, because they tend to repeat the same rule in different questions, but the concept is the same. Goodluck!