Well, there are really a number of options here. The easiest of them would probably be to anoint said scarf with oils to draw luck and success. Making it with that intention in mind also is rather likely to imbue the desired effect to some degree, and of course you could go for a full ritual of blessing, of which there are literally countless iterations of. In my experience with things like this the most solid advice I can give you though is "go with what feels right" intuition is in and of itself probably the best tool one has for most situations, this one included. If you have any specific questions you want clarified on I could offer you my advice, but for such a general question I can't really give any more specific advice.