If they’re just picky I’d probably do cash or giftcard, it takes the guess work out of things. If they’re ungrateful, nothing. I don’t care if they’re family or not, that’s just disrespectful and you don’t deserve anything.
I don’t shop for gifts too often as I’m on a budget. I will for Christmas but it’s only if I’m going to see my sister and her family for the holidays. I’ll only get gifts for her, my brother in law, and nephew and usually take one trip to the mall to get ideas for gifts that I think they will like and then come back a couple of weeks later to buy everything. I have only had one person I had to buy gifts for who was picky and I cut off ties with her years ago. She’d complain if she got something that she didn’t like and throw a fit. I’m glad that I don’t need to get anything for her now. A few of her gifts she got me were actually quite bad as they were mostly clothes that I didn’t really need or want or inappropriate like that taxidermy animal head which really freaked me out but I couldn’t say anything because she told me that it was “very expensive” for her to get and then she made me touch that horrible thing thinking that I’d love it.
If I absolutely had to buy someone like that a present, I would go with a Visa gift card or cash like others mentioned. They can use it literally for whatever they want. Or Amazon card, Gasoline card etc.. Maybe if you know they like a certain place, like Starbucks, getting them a gift card there?