Twice the cost.
Before you make a decision to book a themed wedding, you first need to know right out that something like this is bound to cost you a lot of money and a lot of effort but if you honestly think that it will all be worth it, then by all means, go ahead and indulge yourself. You just need to understand the fact though that it will not come cheap and you need to really be prepared to shell out the big bucks one way or the other if you have any hopes of getting stuff done when it all comes down to it. A typical wedding is expensive in its own right already but a themed wedding will easily double up the costs while you are at it and this is why you need to prepare accordingly and brace yourself for the expenses that are supposed to come along. In events like this, a long engagement will turn out to be a real advantage because it technically means that you have more time to save up and pool your funds in order for you to be able to afford the stuff that you need to pay out for in the first place. Have a serious talk about this with your spouse and make sure that you make a joint decision on whether you would like to proceed with a themed wedding or not after the fact. You might pay out more for Asian wedding photography versus a traditional wedding photography coverage and so on and so forth. Just keep that in mind before you make the decision to really go ahead with it.
Need for an appropriate venue.
You need to nail the venue accordingly if you are ever going to have the chance to make this work out for you in the first place. A themed wedding can be a very nitpicky thing to satisfy when it comes to the venue that you are planning to pick out. It needs to be perfect and all that in order for it to work out at all and this is something that you ought to try to think about and prioritize as much as possible all the time. Go through the site tours. If you plan an Asian themed wedding, for example, you might want to bring along the professional that you hired out for Asian wedding photography in order for you to have a more practiced eye in assessing the place.
Specialists to hire out.
Pick out people who specialize in the specific niche. The wedding industry is a particularly small one in some areas but you will realize that some people have specializations and this is something that you need to figure out and tap into one way or the other if you are ever going to go ahead and nail this the right way at some point or so.
Guests need to be looped in.
Let them know about what you are trying to pull off for the wedding. explain it to them or at least dedicate a page or a paragraph on the invitation to ensure that they understand the theme and how they are going to dress up, if ever.