Make a list
Make a list of all the things that are really important to you in your new home. All members of the family should do this separately. This will mean that you have a coherent idea of everybody’s needs before you start your search.
Have some idea of which points on your list are non-negotiable and which points there might be room for compromise. Everyone is bound to have to give a little and by allowing little flexibility you might even surprise yourself with what you end up purchasing.
I just found out that the banks are not giving mortgages to British Passport holders who are non resident. Only those paying taxes in Spain are granted mortgages.