The first difference you may see is how dressed up most girls are. Dont let that intimidate you. It is typical for a Russian bride to wear heels on a regular basis, to wear dresses and look polished even if she is simply going to a store. Most women here work and coming to office automatically implies wearing dressy clothes. You will also see many of them wear jeans, which is acceptable casual attire for men as well.
While it is common knowledge that most women spend hours in front of the mirror getting ready before a date, clothing choice before a big event is not any less nerve racking for men. If you are taking a Russian bride for a first date, we would strongly recommend to get dressed up. A man in a suit is always an attractive sight, however if you are not big on wearing suits, slacks and shirt will be just fine.
Your choice of attire will also depend on where you are going. For people in the FSU countries going to a restaurant is not an every-day occasion, it implies something special. If you plan on attending an establishment like that, your best bet is to go dressy. If you plan on going to a night club, pants or jeans with a button-up shirt will be fine....