Find your gal a "just for her" gift

Homer's bowling ball
There's an episode of The Simpsons where Homer gives his wife a bowling ball for her birthday. The thing is...she doesn't like bowling. Obviously, Homer picked it out for himself, believing he would get to use it. He even had his own name engraved on it.

That's a rotten gift if I've ever seen one, but it points out a good rule you should follow. When you give your gal a gift, it needs to be something that's just for her...and no one else.

Simple examples
A decoration for the living room or a potted plant for the backyard. Unless she lives alone, these are gifts for the whole family...not just for her.

A pair of tickets to a demolition derby. This is a gift for you...not just for her. At best, this is a gift for the two of you, and that's only if your gal truly loves seeing cars get smashed.

A romantic dinner out to a nice restaurant. This is good if it's in addition to something else, but dinner itself can't be the main gift. Dinner is a gift for the both of you...not just for her.

Here are some better examples. Jewelry, perfume, purse, lounging socks, hair dryer, water bottle, and so on. No one else is going to be using these things, so they're spot on.
They're just for her.

Tricky examples
It may seem like there are some exceptions to this rule, but when you break them down, there really aren't. If you want to impress your gal, you need to follow this rule 100% of the time.

If you give her flowers, she'll stick them in a vase and put them out for everyone to see. It may seem like she's sharing these with everyone else, but she's not. She's not saying, "Hey everyone. Look at what my guy got for all of us to enjoy." Rather, she's showing off the beautiful flowers that you picked/bought for her...and that's a big difference.

Flowers are truly just for her, which is what makes them the most popular and timeless gift of all. What about that other seemingly timeless gift of chocolates though?

We've been conditioned to believe that a heart shaped box of chocolates and Valentine's Day go hand in hand...and they absolutely do. However, chocolates and other sweets are meant to be shared...so they're not just for her.

Definitely get her the chocolates, but don't make that the only thing you give her. Get her something else for the main gift, and buy her the sweets as an extra gift.

Last thought
Make your gal feel special by finding a gift that's just for her. You can give her a "shareable" gift too, but only as an add-on to her main gift.