Ok...I'll give you my take on the process, and this is my personal experience.
I've had three interviews since arriving in Bahrain one informal and two formal. The informal one was held in a office where the guys interviewing me were very relaxed about it all, smoking and having a laugh and I was there for two and a half hours. I wore a pair of jeans and a smart shirt as I knew the format in advance, in any other situation I'd normally wear formal attire, just to be on the safe side. The interview I think went well but it was for a future role as they don't actually need me right now so it's a waiting game on that one. The interviewers were Bahraini men and informal as it was, respect, courtesy and sensitivity to the culture is vital for success. If for some reason, for example they might have a strong accent, you don't understand what the question is, politely ask them to repeat it and listen closely, your brain will fill in the blanks...
I've had few dealings with Bahraini women and am still unsure as to whether to shake their hands or not, some do some don't so I err on the side of caution and wait till the hand is offered before offering mine in return. If you display arrogance, disinterest in the culture or the sensitivities of the people you're dealing with, you shouldn't have gone in the first place.
Knowing the content of your CV inside-out is also vital, don't put anything in it that you cannot elaborate on or go into in more depth. Put your strengths, qualifications, and previous relevant experience at the beginning of your CV, most CV readers lose interest after the first page so it's important to make an impression early.
The second and third interviews I've had were in the past week and they also went well, these were more formal. I wore a suit, did a lot of preparation prior to the interview and that helped a lot. knowing about the company, the business and the culture of the company is very good to know, if it's a family run business then things might be different to those of a larger company. Get your information in order, do practice interviews, I do this every time I get called and it helps to prepare you for the hardest questions. Never be negative in an interview, but do be realistic, everyone has had their ups and downs in their worklife, don't make it sound like you've had a fairytale career to date...they won't believe you...and then you're in trouble. They need to feel that you can be trusted so I think what I call 'Guarded Honesty' is the best policy, be truthful, but don't give everything away. Be respectful to whoever it is that is interviewing you, and be on your guard at all times. Some interviewers can throw in trick questions and it's important not to panic, take a deep breath, think about it for a little bit and give them an answer...that might be: "I don't have an answer for that question, but I'll find out" which is much better than trying and failing to bluff your way out of it. These were expat men (Irish and English) and being Irish myself it made it easier as the language barrier was removed.
I'll add more later.