Seek out parasols - they are delicious, especially just as the cap is beginning to spread. Shaggy parasols too. With giant puffballs the best thing is to slice them quite thickly, dip in beaten egg and breadcrumbs and fry in butter. Yum. Lovely with toast and kippers.   They should still be white all the way through otherwise they are too old. Horse mushrooms, which are related to field mushrooms, are even more delicious, but just check that they have that aniseedy smell when scratched as you don't want to get a rogue Yellow Stainer in your basket which will give you belly-ache. When collecting edible fungi it can be a good idea to keep them the right way up in the basket to avoid soil falling into the gills. Fairy ring toadstools are reputedly delicious but I have yet to try them. Look out for ceps too. Are they the best of all?