Thoroughly familiarise yourself with the requirements of electives with your university. This will help you specify and narrow down your search. Important details to know include; length of placement, required number of hours and supervision, specific learning outcomes, time of year where going abroad will be possible and not interfere with teaching or exams, opportunities for full or partial funding, potential deadlines for applying and application procedure. These will naturally vary depending on your county, university and field of study. You can find other sections on this website which have country- and study-specific information to help you find the information you need.