How do people usually practice practical exams ? Can it be learnt via books or is practice the best way ?
Look up the past practical exams online on the exam boards website. have a read through. it would be impossible to do these practicals e.g. chem ISA at home for practice - it is not necessary. if there is anything you don't understand on the paper then consult your teacher, hopefully he/she could help you to develop your skills in that procedure.
also, for science ISAs, the topic changes every year, so studying past ISAs might not be a good use of your time. it is better to develop your skills in precision and accuracy, as this is mainly what you are being marked on, as well as the ability to follow step-by-step instructions. if you want to read something from a book, the CGP science guides have a 'How Science Works' section which covers some basic investigative skills.
hope this helped xx