There's a difference between good hygiene (health, cleanliness) and good aesthetics (ie: taste). The former is something you'll achieve by cleaning regularly and promoting a healthy vaginal environment (soap, douching, etc. can irritate the flora inside and lead to infections). The latter can be influenced somewhat by diet and habits, but you'll have your own taste and smell native to you which guys will prefer based on their own tastes. This means that one guy may not like how you taste, but another will love it, so don't get discouraged if one is finicky and never accept that there is one "right" way for someone to taste.
If you want to improve your taste overall, reduce consumption of foods like dairy products, meats, heavy spices; also avoid alcohol and tobacco - those are top funk-makers. Increase fruit consumption: pineapples are famous for improving how you taste (guys and gals), but other fruits are great too, like apples, bananas, peaches, strawberries, etc. Remember to hydrate too - that makes the fluids down there flow more freely for licking and lubricating fun.
Good luck, and may the pheremones be with you!