Designing a simple strategy for this game is rather tricky, as asking for a non-physical card the player asked does not explicitly have will almost always guarantee you losing the turn and tells said opponent who does have the card.
The following procedure seems like a safe one:
1. Ask for cards you are sure opponents have belonging to a category they know you have a card from. This will guarantee you keeping your turn and does not reveal any new information.
2. Ask for cards you are sure your opponents have that you have not yet asked for in the previous step, as long as you have a blank which can be locked to each of the categories of those cards. As a result of this, you will be limiting what cards you can have.
3. Ask an opponent for a physical card from a category you must have a card from. This might result in you losing your turn, but does not guarantee it. However, you do not reveal any new information about the cards you own.
4. Ask an opponent for a physical card from a category you do not have a blank locked to yet, if you have a blank that could be from that category. This is also a gamble, but also limits your blanks more.
5. Ask an opponent for a non-physical card from a category you must have at least one card from. This will almost always cost you the turn and will limit the possible cards your blank from the category is if you do not have the physical one. This move is one only to be done if there are no other options.
This strategy might work well, but I cannot be sure without testing it in a simulation, possibly against other strategies as well. The order of steps 2 and 3 could be switched for a strategy which takes more risks, but reveals less about the cards you own.