Depends. You could target Russian citizens with strong ties to Putin with asset seizures like Roman Abramovich. Seizing Chelsea F.C. and handing it over to fans would be quite popular.
What would this kind of sanction achieve? Do you expect that a friend of Putin will go to him and then ask him to stop a War? Right now in his own circle of friends, there is nobody more powerful than Putin and their money does not matter right now. The war will not be stopped because some friends will have their assets frozen or even lost. Global Power > Friends Money. To stop this war one has to show a bigger power. Some other type of sanctions needs to be considered.
Don't get fooled, they are only "friends" because they have common business and goals. Average Joe from the street is not going to be their "friend" because he would not bring anything to the table.
Friends money is part of that power, taking that money away makes whole group weaker, because it is not "evil villain in a cave", world does not work that way. It is connections and groups of people.
What would stop Russia to retaliate in that case? Every western company property in Russia would become a fair game, including e.g Bidens son and his property in Ukraine.
The west not having the stomach for any real sanctions that also hurt them in return is exactly why Putin was confident enough to start the invasion. The only way non-violent way to stop it (besides an internal uprising) is to make exactly to make it clear that Putin miscalculated.
