The antonyms for the phrase "toss ideas around" would be to ignore, reject, or dismiss concepts without consideration. Alternatively, one could also keep their ideas to themselves, which would result in no discussion or brainstorming taking place. Another opposite would be to follow a strict, predetermined plan without open discussion, which would not allow any new or creative ideas to surface. Instead of tossing ideas around, one could also impose their ideas onto others or shut down any conflicting opinions, which could lead to a lack of diversity in solutions. Ultimately, embracing the opposite of "tossing ideas around" could hinder progress and innovation within a team or organization.