You only have to watch TV programmes like 'A Place In The Sun' to realise that many people buy overseas property on the basis of a single visit to the area. Some appear even to buy on their first visit to the Country!
I am not suggesting that this is usual, but I think it does happen quite a lot and would warn would-be house-hunters to do a little more research than they could possibly do in a single visit.
So, what's wrong with buying on impulse? This notion might lend a little more romance to the purchase transaction than perhaps a lengthy research and evaluation process might, and property prices have been rising steadily for years (suggesting that it's not such a bad thing if you make a mistake as you can always sell again). But - there will be a significant emotional, as well as financial, impact on you and your family when you buy abroad, and this will take its toll quickly if you are unhappy with the area you have bought into.
My advice then, is to do what you would do when buying in your home country....
Go visit the area a few times, making sure that you visit 'out of season' as well if you intend to be in the property at these times. An area can look and feel so different in November to how it did when you holidayed there in August!
Get to know the good locales, and focus your attentions there.
Perhaps rent a house there for a while before buying.
Decide what your own requirements are, rank them in terms of importance, and then measure each property location against them. For example, do you want to live in a town, near to local shops, on the coast etc. Are road and rail links important. How easy is it to get to (especially in a hurry)?
If you are not as young as you used to be, perhaps the close proximity of a hospital, or other medical resources, is more important than it might have been a few years ago.
If you are buying for partly investment reasons, then has the area just experienced a sharp upturn in popularity (and prices) or is it about to?