You can look up some cake/cookie recipes for offerings if you want but provided you chose it out of love and not necessity [Example, choosing to give your favourite cookie, over running into the kitchen and going 'good enough'.] We can't all bake and we don't all have the time, just keep an open mind. When it comes to food offerings maybe put a little aside from dinner to give, or if you're out for a walk and see a bakery, pop in and buy something just for the Lord and Lady you think they'd like.
You can also do non-food offerings of just about anything. As lavenderc pointed out they are our parents. What loving parent would be handed a macaroni necklace by their 3 year old throw it back and go 'bah! You call this a gift?!' No, and neither would the gods provided it's out of love. Again, you're in a hurry and light some incense you know they like, that's fine, if you're in a hurry and grab a rock you found and throw it on the altar, not so much. Another thing you can do, when you're out on a walk, pick up little things that catch your eye as offerings. You see an interesting rock shaped like a heart, pick it up, you see the first flower of the season [depending on your views] pick it. A feather, a leaf, a branch, if it peaks your interests pick it up. Perhaps decorate your altar. If you feel the rock or stick or whatever is too plain, decorate it. Ostara is coming up, paint some eggs and present them as a gift.