For these unis?
^^^ First of all start by looking through this thread and ask any questions on there if you haven't already. I don't know what Manchester and Keele are like and I haven't started prepping for Aston but for SGUL it's very much ethics and scenarios based for their MMIs. You can start off by prepping for questions like 'why med?' or 'why SGUL?', then look at the qualities of a doctor and include work experience examples. Then look at case studies and the NHS and hot topics and then ethics and the 4 pillars. That's just a start though, use TSR, Medic Portal and other websites or maybe get the ISC interview book. Hope this helps