I applied for and got this visa for my GF. You are better to show she has no money. If she has no money and knows nobody in UK she cannot abscond. I booked everything in advance. Plnes, hotels, car hire, shows etc. I also proved a long standing relationship with pictures and letters from family and friends. I also wrote a guarantee letter that I would meet all her costs and ensure her return to Thailand. We showed her bank account with her monthly wages going in and as quickly dissapearing. I showed that I had enough funds in Thailand and UK. She was shown on the house book of my owned condo. I copied deeds and house book
(translations to english)
A word of warning. I saw a very beautiful girl at the office when I went to pick up the visa. She worked in a good job for the government and had a lot of money in the bank and her own condo. She just wanted a holiday in UK and see some friends. She was refused.she said she was staying with friends) If she knows anyone Thai there you will not suceed. Possible threat of absconding. I had spent over £7,000 on that holiday going to Ireland
(Repblic) too, which a UK visa allows. If you book in advance then you take a chance, so make sure it is airtight. I did not use an agent.
The main thing you have to show is a long standing genuine relationship. If you feel you cannot do that , then "don't apply as you will not suceed"! And waste money.