hello vinmer,
from my experience,what i did to apply a visitors visa was... i let my fiancee to write a letter in hand written ,addressed to BRITISH EMBASSY MANILA, that he is inviting me as his visitor for the purpose of letting me experience the culture and traditions here and at the same time sight seeing...and he is willing to accomodate me in his house while here in uk...and i ask xerox copy of his passport the page contained his picture and his signature and also the pages that hv been stamped.whats important i think is to prove the eco citizenship status of the sponsor.anf also i ask from my fiancee his bank statements 6 mos going back up to the month of my application..thats the only things i asked from my fiancee..Maybe i was granted coz i showed also documents from my side to proved that i have all the reasons really to go back and no intention to live here in my whole life lol....im willing to answer all ur querries regarding visitors visa application,based from my experiences coz i did applied twice already and all was granted...