Writing a 90th birthday card can be challenging, but there are many options to choose from. Here are some ideas from the search results:

1. Cheerful quotes or greetings: You can use one of the cheerful quotes or greetings from to express your wishes. For example, "Happy 90th Birthday! Its wonderful being able to share such a special birthday with someone like you."

2. Funny 90th birthday wishes: If the person has a good sense of humor, you can use one of the funny 90th birthday wishes from. For example, "You’re not old, you’re a classic."

3. Sentimental 90th birthday wishes: You can use one of the sentimental 90th birthday wishes from to express your feelings of friendship and love. For example, "When you look back over 90 years, I hope that your memories are warm ones. When you celebrate today, I hope that your heart is filled with love and joy. When you look forward to the future, I hope that all your dreams and wishes come true."

4. Heartfelt wishes: You can use one of the heartfelt wishes from. For example, "On your 90th birthday, may God bless you with abundant joy, good health, and peace that surpasses all understanding. Happy birthday!"

5. Personalized wishes: You can make your wishes unique by writing them down on a greeting card and handing them in person. You can use the ideas from and to craft your own personalized wishes by adding beautiful memories you have shared with them.

Remember to keep your message positive, interesting, and engaging. You can also include a small gift or a photo to make the card more special.