Remember this and you can never go wrong. Women want to feel special. Do something that would make her feel special. Something that would have taken you out of your "norm or comfort zone" to provide something specifically just for her. Dont do anything that would have her think you could have done this "good deed" for anybody else. She is not testing you. Every man buys flowers - gifts - candy - teddie bears and such. These things do not "speak" specificly to her. She just wants you to do something "different" and that says she is not like "everybody else"

Here are some ideas:

Cook her dinner. If you cant boil water to save your life, take a cooking class together.
Use Groupon. They have great ideas and they can save you money.
Take her on a date: https://couples.howaboutwe.com/
Create a playlist on Pandora.com of all her favorite songs or type of music she loves
Sing to her. Dress up like her favorite music artist and sing her favorite song as that particular artist. It doesnt matter if you have a voice or not.
Rent a convertible car and take a scenic drive somewhere and let her hair blow in the wind
Or rent a luxury car for a day and take her out to dinner. Pretend to be royalty for a day and you guys have to stay in character as the people you'll portray
Movies in the park. Find one and go have a picnic
Take her dancing. Even if you cant dance - its just the mere hought that you are willing to go beyond your comfort zone to please her.

Its pretty easy when you think about it. You know what she loves and you know what makes her smile. Women want to feel and know that you are still "dating" them. Dont take her on dates that you want to do. Take her on dates that she wants to do. My wife and I go on "If money was no object dates". We go window shopping. Try on expensive clothes - test drive expensive cars - go to expensive restaurants just to share a dessert dish and a glass of wine (or water)

Heres an idea. Cook dinner for her (surprise 1) ...afterwards tell her youre taking her out for dessert (surprise 2)...but you guys have to get dressed up for it (surprise 3). After you're dressed, you step outside to your "rented" luxury car for the day (surprise 4). You pull up to the valet and the "expensive" restaurant that youve made reservations for (surprise 5). Youve been seated and the pre-ordered dessert arrives in 10 minutes. (surprise 6) Slowly enjoy the dessert and tell her again why you love her.

Its just that easy.