For a business like yours, location and reputation are the single biggest factors. People will walk by and decide to eat. But that's just my view - you should ask your customers - why did you decide to eat here? how did you hear about my restaurant?
the other things I've seen people do to good effect is to put cards/menus/discount cards at nearby hotels or resorts. Its a captive audience and they have to eat out - so - that's an easy one. Another is to get more reviews on more websites - chowhound for americans but there must be similar for french, dutch and english visitors. Also make sure your restaurant comes up on google maps (preferably with 4 stars) and on google maps mobile! In a pinch that's what I use when traveling.
the other things I've seen people do to good effect is to put cards/menus/discount cards at nearby hotels or resorts. Its a captive audience and they have to eat out - so - that's an easy one. Another is to get more reviews on more websites - chowhound for americans but there must be similar for french, dutch and english visitors. Also make sure your restaurant comes up on google maps (preferably with 4 stars) and on google maps mobile! In a pinch that's what I use when traveling.