it is just more playing around with extracts. i just add coconut extract to my favorite regular sugar cookie recipe (for me, that is the "cookie craft" recipe). i add 1-2 teaspoons of coconut extract. and for coconut and banana, i just use plain old mccormick's extracts that i can purchase at the grocery store.
i use lorann oils for some of the more unusual flavors. and you use way less of these than you do extracts because they are more concentrated.
if you want to make lime flavored sugar cookies you can use lime zest or purchased lime oil. i would advise against using the actual lime zest (the way we do with lemon zest) in dough . the lime zest turns brown when you bake it and can be kinda unattractive. what you can do is put your sugar and lime zest in a sealed containter for 24 hours (giving it a shake every now and then) and let the sugar absorb the lime oil from the zest. then strain out the zest and use your lime sugar as normal (it will appear a bit green, but your cookies won't be green, lol). for lemon, go ahead and keep the zest it as it bakes up fine.