It's late,i have a 'orrible toofache',so i hope my post makes some sense :p
Firstly if you have a fussy dog,i would go with a meat based food,,not a grain based one as are most dry foods.I think the only dogs who enjoy plain dry food,no matter what the ingredients are,are the true chow hounds.
I see nothing wrong with sticking with same high quality dry food and adding tasty,healthy toppers to it.However it is very important to add the extra's at the first feeding.If he refuses, do NOT pick it up and add something to tempt him to eat or else he will always refuse it waiting for you to add something better.Make sure he cant refuse his meal in the first instance.
Plain dry food is pretty unpalatable,and feeding nothing but is not a healthy regime IMHO.My dogs would eat their dry food on it's own but i rarely serve it up to them,i always add some meat,veggies,cottage cheese,organs(baked liver is a favourite),green tripe(not the human grade stuff from the butcher),tinned fish. They also get rmb's on a daily basis.This way they are getting a formulated food,but also getting the benefits of fresh foods aswell.
I have a friend with a fussy dog who once went 5 days and nights without eating a scrap,she tried the 10 minute rule which just did not work.She has adopted the above regime and her dog is a much better eater now and rarely misses a meal,she only eats one meal a day,but it's better than nothing.
Here is an example of a meat based food,and the one i feed:
De-boned chicken, chicken meal, turkey meal, russet potato, lake whitefish, chicken fat (preserved with mixed tocopherals, a natural source of vitamin E), sweet potato, whole eggs, turkey, salmon meal, salmon and anchovy oils, salmon, natural chicken flavor, sunflower oil, sun-cured alfalfa, dried brown kelp, carrots, spinach, peas, tomatoes, apples, psyllium, dulse, chicory root, licorice root, tumeric root, fenugreek, glucosamine HCl, cranberries, black currants, marigold flowers, sweet fennel, zea mays, peppermint leaf, chamomile flowers, dandelion, summer savory, rosemary extract, chondroitin sulfate, rosehips, vitamin supplements (vitamin E, choline chloride, vitamin A, vitamin D3, thiamine mononitrate, vitamin B12, folic acid, biotin), sea salt, minerals (iron proteinate, zinc proteinate, manganese proteinate, copper proteinate), direct fed microbials (dried Lactobacillus acidophilus fermentation product, dried Enterococcus faecium fermentation product).
Orijen Puppy Food does not contain artificial preservatives.
http://www.zooplus.co.uk/shop/dogs/dry_dog_food/orijenOh,and i urge you to give the tripe a go,i dont know any dogs who dont love the stuff,plus it is very healthy.