Well, as far as I know you cannot create new seeds for the Waves blockchain, but use old, existing seeds to create new accounts.
https://waves.exchange/sign-up/When you click on Software. Then you click on create password and then create account. You would then be given a choice of a few waves addresses to choose from. Then you click next or okay. Then it goes to a new waves account and you get message on bottom corner to write down you seed and save it.
Can anyone here confirm this? Someone from waves support said you could create as many seed phrase accounts you want on the waves_exchange client or the waves exchange website.