Can you elaborate on what your budget is per person? The ideas people come up with may be easier if we know your budget is $25 per person, or $50 per person. I consider up to $30 an inexpensive gift (for an adult), and $50 a moderate price point...but others may consider under $75 inexpensive.
For the female, if she likes cooking or baking you can put together a nice little bundle. Perhaps a specialty cooking/baking book (cupcakes are all the rage right now!) and a few tools or supplies that go with the style of the book. For instance, if you got a cupcake book, you could purchase decorative cupcake liners, a nice spatula, maybe fun sprinkles (not
Walmart style, but the really gorgeous specialty types), and a pretty dishtowel.
I once got my mother a set of velvet makeup/toiletry bags from Pottery Barn that could be monogrammed.
A decorative neck scarf or casual jewelry.
A nice collection of gourmet tea bags (or loose leaf tea with the accessories needed). Almost everyone drinks tea.
A pretty throw could go over nicely.
She may also appreciate a collection of specialty cooking spices & salts, like Pink Himalayan Sea Salt, etc.
Definitely stay away from anything scented (like beauty products) because everyone has different preferences.
...For the men, that is more difficult.
Either of them may like some sort of all-in-one tool that does...cool stuff. lol
My husband already had flashlights, but he was ecstatic when I bought him 1 large and 1 tiny Magnalite with LED lights rather than the normal bulb flashlights. I got them at Costco last year for about $25 I think. There are also neat flashlights called Gorillatorch flexible tripod flashlights that are awesome! Could be great gifts for either.
The older man probably grills, so you could do a few different dry rubs. Or several different BBQ sauces, both of those usually are hits with men.
Again, for the older man, specialty beer would be good if you happen to know he likes beer.
For the 18 year old, pretty much anything from ThinkGeek.com would be perfect. lol
So, on the beer related note, I just found a bottle opener with cap catcher for $10 online. It catches the caps when you open it.
If the older one likes wine, I think you can even buy little mini bottles in a collection as a wine flight. That might be fun...maybe the woman would like that also.