one thing about cooking for two is wastage because the portions of food you buy are usually more than enough for two. so how do i reduce wastage? one way is to cook as often as possible cos that way, you can use the leftover (uncooked of cos) ingredients and re-invent them into new dishes.
for eg, when i made the sukiyaki, there were leftover tofu, tang o, mushrooms, chinese cabbage and udon so the next day i cooked tom yum udon soup for lunch =D
and when i cooked the okonomiyaki, i used 1/4 cabbage (i bought 1/2) so i will probably fry the rest with dried shrimps or cook cabbage soup. the japanese yam will be great in a soup =)
i might cook chicken in a biscuit chicken today and if i do, i'd probably not use up all the fillets in the packet. i'd keep two for lunch the next day (make porridge or something) or make chicken mayo for breakfast sandwich.
so i guess, you just have to plan and be creative and you'll be able to use up the ingredients ^^