Regards,
I think that first you need to have a idea, something what is yours, something what you think that will draw people to read. Your text don t need to be long, just short and effective, and of course, realistic and honest. But I think that you need to create ads,as you see the SFI, and this kind of job- that need to be your personal creation. Nice picture, and honest text in ad, is a winning combination. Good luck!
